diff --git a/paddle/fluid/translator/op_translator.cc b/paddle/fluid/translator/op_translator.cc
index 222edc45e68f6..c8ce1ffdcab12 100644
--- a/paddle/fluid/translator/op_translator.cc
+++ b/paddle/fluid/translator/op_translator.cc
@@ -110,8 +110,8 @@ inline ir::Operation* InsertSliceOperationForTarget(
       defining_info.value.type().dyn_cast<ir::VectorType>();
   ir::Operation* operation =
       ir::Operation::create({defining_info.value},
-                            {src_vec_type[defining_info.idx_in_vector]},
                             op_attribute_map,
+                            {src_vec_type[defining_info.idx_in_vector]},
                             op_info);
   program->InsertOp(operation);
   ir::OpResult target_op_result = operation->GetResultByIndex(0);
@@ -136,7 +136,7 @@ inline ir::Operation* InsertCombineOperationForTarget(
   }
   ir::Type target_vec_type = ir::VectorType::get(ctx, types_in_vec);
   ir::Operation* operation =
-      ir::Operation::create(src_values, {target_vec_type}, {}, op_info);
+      ir::Operation::create(src_values, {}, {target_vec_type}, op_info);
   program->InsertOp(operation);
   return operation;
 }
@@ -281,7 +281,7 @@ ir::Operation* GeneralOpHandler(ir::IrContext* ctx,
   std::tie(op_output_types, arg_to_idx) = GenerateOperationOutput(ctx, op_desc);
   auto op_info = LoopkUpOpInfo(ctx, op_desc);
   ir::Operation* operation =
-      ir::Operation::create(op_inputs, op_output_types, {}, op_info);
+      ir::Operation::create(op_inputs, {}, op_output_types, op_info);
   program->InsertOp(operation);
   RecordOpResultMapping(param_map, op_desc, operation, arg_to_idx);
 
@@ -299,7 +299,7 @@ ir::Operation* FeedOpHandler(ir::IrContext* ctx,
   std::tie(op_output_types, arg_to_idx) = GenerateOperationOutput(ctx, op_desc);
   auto op_info = LoopkUpOpInfo(ctx, op_desc);
   ir::Operation* operation =
-      ir::Operation::create(op_inputs, op_output_types, {}, op_info);
+      ir::Operation::create(op_inputs, {}, op_output_types, op_info);
   program->InsertOp(operation);
   RecordOpResultMapping(param_map, op_desc, operation, arg_to_idx);
 
@@ -315,7 +315,7 @@ ir::Operation* FetchOpHandler(ir::IrContext* ctx,
   OpOutputTypeList op_output_types = {};
   auto op_info = LoopkUpOpInfo(ctx, op_desc);
   ir::Operation* operation =
-      ir::Operation::create(op_inputs, op_output_types, {}, op_info);
+      ir::Operation::create(op_inputs, {}, op_output_types, op_info);
   program->InsertOp(operation);
 
   return operation;
diff --git a/paddle/fluid/translator/program_translator.cc b/paddle/fluid/translator/program_translator.cc
index f3af3a3db54e4..85a09b2da03aa 100644
--- a/paddle/fluid/translator/program_translator.cc
+++ b/paddle/fluid/translator/program_translator.cc
@@ -79,7 +79,7 @@ void ProgramTranslator::ExtractParameterFromSingleBlock(
     };
     ir::Type translated_var_type = type_translator[var->GetType()](ctx, *var);
     ir::Operation* operation = ir::Operation::create(
-        {}, {translated_var_type}, op_attribute_map, op_info);
+        {}, op_attribute_map, {translated_var_type}, op_info);
     program->InsertOp(operation);
     param_map[var->Name()] =
         VariableDefiningInfo(operation->GetResultByIndex(0));
diff --git a/paddle/ir/core/block.cc b/paddle/ir/core/block.cc
index 62263a8f1a383..0a11fb81f5fa7 100644
--- a/paddle/ir/core/block.cc
+++ b/paddle/ir/core/block.cc
@@ -16,6 +16,20 @@
 
 namespace ir {
 Block::~Block() { clear(); }
+void Block::push_back(Operation *op) {
+  op->set_parent(this);
+  ops_.push_back(op);
+}
+
+void Block::push_front(Operation *op) {
+  op->set_parent(this);
+  ops_.push_front(op);
+}
+
+Block::iterator Block::insert(const_iterator iterator, Operation *op) {
+  op->set_parent(this);
+  return ops_.insert(iterator, op);
+}
 
 void Block::clear() {
   while (!empty()) {
diff --git a/paddle/ir/core/block.h b/paddle/ir/core/block.h
index 3bc4ef8247881..09b4b584b66a1 100644
--- a/paddle/ir/core/block.h
+++ b/paddle/ir/core/block.h
@@ -14,18 +14,23 @@
 
 #pragma once
 
+#include <cstddef>
 #include <list>
 #include "paddle/ir/core/operation.h"
 
 namespace ir {
+class Region;
+
 class Block {
  public:
   using iterator = std::list<Operation *>::iterator;
   using reverse_iterator = std::list<Operation *>::reverse_iterator;
+  using const_iterator = std::list<Operation *>::const_iterator;
 
   Block() = default;
   ~Block();
 
+  Region *parent() const { return parent_; }
   bool empty() const { return ops_.empty(); }
   size_t size() const { return ops_.size(); }
 
@@ -34,21 +39,22 @@ class Block {
   reverse_iterator rbegin() { return ops_.rbegin(); }
   reverse_iterator rend() { return ops_.rend(); }
 
-  Operation *back() { return ops_.back(); }
-  Operation *front() { return ops_.front(); }
-  void push_back(Operation *op) { ops_.push_back(op); }
-  void push_front(Operation *op) { ops_.push_front(op); }
-  std::list<Operation *>::iterator insert(
-      std::list<Operation *>::const_iterator iterator, Operation *op) {
-    return ops_.insert(iterator, op);
-  }
+  Operation *back() const { return ops_.back(); }
+  Operation *front() const { return ops_.front(); }
+  void push_back(Operation *op);
+  void push_front(Operation *op);
+  iterator insert(const_iterator iterator, Operation *op);
   void clear();
 
  private:
   Block(Block &) = delete;
-  void operator=(Block &) = delete;
+  Block &operator=(const Block &) = delete;
+
+  friend class Region;
+  void set_parent(Region *parent) { parent_ = parent; }
 
  private:
+  Region *parent_;              // not owned
   std::list<Operation *> ops_;  // owned
 };
 }  // namespace ir
diff --git a/paddle/ir/core/builder.cc b/paddle/ir/core/builder.cc
index 107b846774779..13c16db6a6b74 100644
--- a/paddle/ir/core/builder.cc
+++ b/paddle/ir/core/builder.cc
@@ -13,6 +13,7 @@
 // limitations under the License.
 
 #include "paddle/ir/core/builder.h"
+#include "paddle/ir/core/region.h"
 
 namespace ir {
 Operation *Builder::insert(Operation *op) {
@@ -25,17 +26,16 @@ Operation *Builder::insert(Operation *op) {
 }
 
 /// Create an operation given the fields represented as an OperationState.
-Operation *Builder::create(const OperationArgument &argument) {
-  return insert(Operation::create(argument));
+Operation *Builder::create(OperationArgument &&argument) {
+  return insert(Operation::create(std::move(argument)));
 }
 
 /// Creates an operation with the given fields.
 Operation *Builder::create(const std::vector<ir::OpResult> &inputs,
-                           const std::vector<ir::Type> &output_types,
                            const AttributeMap &attribute,
+                           const std::vector<ir::Type> &output_types,
                            ir::OpInfo op_info) {
-  OperationArgument argument(op_info, inputs, output_types, attribute);
-  return create(argument);
+  return create(OperationArgument(inputs, attribute, output_types, op_info));
 }
 
 }  // namespace ir
diff --git a/paddle/ir/core/builder.h b/paddle/ir/core/builder.h
index e1f3de2b72691..7bd187961c3ce 100644
--- a/paddle/ir/core/builder.h
+++ b/paddle/ir/core/builder.h
@@ -47,12 +47,12 @@ class Builder {
   Operation *insert(Operation *op);
 
   /// Creates an operation given the fields represented as an OperationState.
-  Operation *create(const OperationArgument &argument);
+  Operation *create(OperationArgument &&argument);
 
   /// Creates an operation with the given fields.
   Operation *create(const std::vector<ir::OpResult> &inputs,
-                    const std::vector<ir::Type> &output_types,
                     const AttributeMap &attribute,
+                    const std::vector<ir::Type> &output_types,
                     ir::OpInfo op_info);
 
   /// Create an operation of specific op type at the current insertion point.
@@ -60,7 +60,7 @@ class Builder {
   OpTy create(Args &&...args) {
     OperationArgument argument(context_->GetRegisteredOpInfo(OpTy::name()));
     OpTy::build(*this, argument, std::forward<Args>(args)...);
-    Operation *op = create(argument);
+    Operation *op = create(std::move(argument));
     return op->dyn_cast<OpTy>();
   }
 
diff --git a/paddle/ir/core/builtin_op.h b/paddle/ir/core/builtin_op.h
index ffe357ed9e993..3a7f77b00aab6 100644
--- a/paddle/ir/core/builtin_op.h
+++ b/paddle/ir/core/builtin_op.h
@@ -17,6 +17,7 @@
 #include "paddle/ir/core/op_base.h"
 
 namespace ir {
+
 ///
 /// \brief GetParameterOp: OpResult = GetParameterOp({StrAttribute,
 /// StrAttribute})
diff --git a/paddle/ir/core/operation.cc b/paddle/ir/core/operation.cc
index 4c62ed811cc96..4f9575c03d349 100644
--- a/paddle/ir/core/operation.cc
+++ b/paddle/ir/core/operation.cc
@@ -15,23 +15,31 @@
 #include "paddle/ir/core/operation.h"
 #include "paddle/ir/core/dialect.h"
 #include "paddle/ir/core/program.h"
+#include "paddle/ir/core/region.h"
 #include "paddle/ir/core/utils.h"
 
 namespace ir {
-Operation *Operation::create(const OperationArgument &argument) {
-  return create(argument.inputs_,
-                argument.output_types_,
-                argument.attribute_,
-                argument.info_);
+Operation *Operation::create(OperationArgument &&argument) {
+  Operation *op = create(argument.inputs,
+                         argument.attribute,
+                         argument.output_types,
+                         argument.info,
+                         argument.regions.size());
+
+  for (size_t index = 0; index < argument.regions.size(); ++index) {
+    op->GetRegion(index).TakeBody(std::move(*argument.regions[index]));
+  }
+  return op;
 }
 
 // Allocate the required memory based on the size and number of inputs, outputs,
 // and operators, and construct it in the order of: OpOutlineResult,
 // OpInlineResult, Operation, Operand.
 Operation *Operation::create(const std::vector<ir::OpResult> &inputs,
-                             const std::vector<ir::Type> &output_types,
                              const AttributeMap &attribute,
-                             ir::OpInfo op_info) {
+                             const std::vector<ir::Type> &output_types,
+                             ir::OpInfo op_info,
+                             size_t num_regions) {
   // 0. Verify
   if (op_info) {
     op_info.verify(inputs, output_types, attribute);
@@ -50,7 +58,9 @@ Operation *Operation::create(const std::vector<ir::OpResult> &inputs,
           : sizeof(detail::OpInlineResultImpl) * num_results;
   size_t operand_mem_size = sizeof(detail::OpOperandImpl) * num_operands;
   size_t op_mem_size = sizeof(Operation);
-  size_t base_size = result_mem_size + op_mem_size + operand_mem_size;
+  size_t region_mem_size = num_regions * sizeof(Region);
+  size_t base_size =
+      result_mem_size + op_mem_size + operand_mem_size + region_mem_size;
   // 2. Malloc memory.
   char *base_ptr = reinterpret_cast<char *>(aligned_malloc(base_size, 8));
   // 3.1. Construct OpResults.
@@ -65,8 +75,8 @@ Operation *Operation::create(const std::vector<ir::OpResult> &inputs,
     }
   }
   // 3.2. Construct Operation.
-  Operation *op =
-      new (base_ptr) Operation(num_results, num_operands, attribute, op_info);
+  Operation *op = new (base_ptr)
+      Operation(attribute, op_info, num_results, num_operands, num_regions);
   base_ptr += sizeof(Operation);
   // 3.3. Construct OpOperands.
   if ((reinterpret_cast<uintptr_t>(base_ptr) & 0x7) != 0) {
@@ -76,13 +86,27 @@ Operation *Operation::create(const std::vector<ir::OpResult> &inputs,
     new (base_ptr) detail::OpOperandImpl(inputs[idx].impl_, op);
     base_ptr += sizeof(detail::OpOperandImpl);
   }
-
+  // 3.4. Construct Regions
+  if (num_regions > 0) {
+    op->regions_ = reinterpret_cast<Region *>(base_ptr);
+    for (size_t idx = 0; idx < num_regions; idx++) {
+      new (base_ptr) Region(op);
+      base_ptr += sizeof(Region);
+    }
+  }
   return op;
 }
 
 // Call destructors for OpResults, Operation, and OpOperands in sequence, and
 // finally free memory.
 void Operation::destroy() {
+  // Deconstruct Regions.
+  if (num_regions_ > 0) {
+    for (size_t idx = 0; idx < num_regions_; idx++) {
+      regions_[idx].~Region();
+    }
+  }
+
   // 1. Get aligned_ptr by result_num.
   uint32_t max_inline_result_num =
       detail::OpResultImpl::GetMaxInlineResultIndex() + 1;
@@ -136,15 +160,16 @@ void Operation::destroy() {
 
 IrContext *Operation::ir_context() const { return op_info_.ir_context(); }
 
-Operation::Operation(uint32_t num_results,
+Operation::Operation(const AttributeMap &attribute,
+                     ir::OpInfo op_info,
+                     uint32_t num_results,
                      uint32_t num_operands,
-                     const AttributeMap &attribute,
-                     ir::OpInfo op_info) {
-  num_results_ = num_results;
-  num_operands_ = num_operands;
-  attribute_ = attribute;
-  op_info_ = op_info;
-}
+                     uint32_t num_regions)
+    : attribute_(attribute),
+      op_info_(op_info),
+      num_results_(num_results),
+      num_operands_(num_operands),
+      num_regions_(num_regions) {}
 
 ir::OpResult Operation::GetResultByIndex(uint32_t index) const {
   if (index >= num_results_) {
@@ -198,4 +223,9 @@ std::string Operation::print() {
 
 std::string Operation::op_name() const { return op_info_.name(); }
 
+Region &Operation::GetRegion(unsigned index) {
+  assert(index < num_regions_ && "invalid region index");
+  return regions_[index];
+}
+
 }  // namespace ir
diff --git a/paddle/ir/core/operation.h b/paddle/ir/core/operation.h
index 7e5993ada74b5..d5804ee9e43eb 100644
--- a/paddle/ir/core/operation.h
+++ b/paddle/ir/core/operation.h
@@ -15,7 +15,6 @@
 #pragma once
 
 #include <iostream>
-#include <vector>
 #include "paddle/ir/core/op_info.h"
 #include "paddle/ir/core/operation_utils.h"
 #include "paddle/ir/core/type.h"
@@ -24,6 +23,7 @@
 namespace ir {
 class OpBase;
 class Program;
+class Block;
 
 class alignas(8) Operation final {
  public:
@@ -34,16 +34,19 @@ class alignas(8) Operation final {
   /// used in conjunction.
   ///
   static Operation *create(const std::vector<ir::OpResult> &inputs,
-                           const std::vector<ir::Type> &output_types,
                            const AttributeMap &attribute,
-                           ir::OpInfo op_info);
-  static Operation *create(const OperationArgument &op_argument);
+                           const std::vector<ir::Type> &output_types,
+                           ir::OpInfo op_info,
+                           size_t num_regions = 0);
+  static Operation *create(OperationArgument &&op_argument);
 
   ///
   /// \brief Destroy the operation objects and free memory by create().
   ///
   void destroy();
 
+  Block *parent() const { return parent_; }
+
   IrContext *ir_context() const;
 
   ir::OpResult GetResultByIndex(uint32_t index) const;
@@ -60,6 +63,8 @@ class alignas(8) Operation final {
 
   uint32_t num_operands() const { return num_operands_; }
 
+  uint32_t num_regions() const { return num_regions_; }
+
   std::string op_name() const;
 
   template <typename T>
@@ -83,11 +88,15 @@ class alignas(8) Operation final {
     parent_program_ = parent_program;
   }
 
+  /// Returns the region held by this operation at position 'index'.
+  Region &GetRegion(unsigned index);
+
  private:
-  Operation(uint32_t num_results,
+  Operation(const AttributeMap &attribute,
+            ir::OpInfo op_info,
+            uint32_t num_results,
             uint32_t num_operands,
-            const AttributeMap &attribute,
-            ir::OpInfo op_info);
+            uint32_t num_regions);
 
   template <typename T, typename Enabler = void>
   struct CastUtil {
@@ -96,6 +105,9 @@ class alignas(8) Operation final {
     }
   };
 
+  friend class Block;
+  void set_parent(Block *parent) { parent_ = parent; }
+
   template <typename T>
   struct CastUtil<
       T,
@@ -107,11 +119,13 @@ class alignas(8) Operation final {
 
   OpInfo op_info_;
 
-  uint32_t num_results_ = 0;
-
-  uint32_t num_operands_ = 0;
+  const uint32_t num_results_ = 0;
+  const uint32_t num_operands_ = 0;
+  const uint32_t num_regions_ = 0;
 
+  Region *regions_{nullptr};
   Program *parent_program_{nullptr};
+  Block *parent_{nullptr};
 };
 
 }  // namespace ir
diff --git a/paddle/ir/core/operation_utils.cc b/paddle/ir/core/operation_utils.cc
index e61b368bafa81..d68c037000a7f 100644
--- a/paddle/ir/core/operation_utils.cc
+++ b/paddle/ir/core/operation_utils.cc
@@ -13,19 +13,11 @@
 // limitations under the License.
 
 #include "paddle/ir/core/operation_utils.h"
+#include "paddle/ir/core/region.h"
 
 namespace ir {
-OperationArgument::OperationArgument(IrContext* ir_context, std::string name) {
-  info_ = ir_context->GetRegisteredOpInfo(name);
+OperationArgument::OperationArgument(IrContext* ir_context,
+                                     const std::string& name) {
+  info = ir_context->GetRegisteredOpInfo(name);
 }
-
-OperationArgument::OperationArgument(OpInfo info,
-                                     const std::vector<OpResult>& operands,
-                                     const std::vector<Type>& types,
-                                     const AttributeMap& named_attr)
-    : info_(info),
-      inputs_(operands),
-      output_types_(types),
-      attribute_(named_attr) {}
-
 }  // namespace ir
diff --git a/paddle/ir/core/operation_utils.h b/paddle/ir/core/operation_utils.h
index 8deeec781e840..fb43e8a1ca069 100644
--- a/paddle/ir/core/operation_utils.h
+++ b/paddle/ir/core/operation_utils.h
@@ -16,6 +16,7 @@
 
 #include "paddle/ir/core/builtin_attribute.h"
 #include "paddle/ir/core/op_info.h"
+#include "paddle/ir/core/region.h"
 #include "paddle/ir/core/type.h"
 #include "paddle/ir/core/value_impl.h"
 
@@ -30,18 +31,25 @@ using AttributeMap = std::unordered_map<std::string, Attribute>;
 // This represents an operation arguments in an combined form, suitable for use
 // with the builder APIs.
 struct OperationArgument {
-  OpInfo info_;
-  std::vector<OpResult> inputs_;
-  std::vector<Type> output_types_;
-  AttributeMap attribute_;
+  std::vector<OpResult> inputs;
+  AttributeMap attribute;
+  std::vector<Type> output_types;
+  OpInfo info;
+  std::vector<std::unique_ptr<Region>> regions;
 
  public:
-  OperationArgument(IrContext* ir_context, std::string name);
-  explicit OperationArgument(OpInfo info) : info_(info) {}
-  OperationArgument(OpInfo info,
-                    const std::vector<OpResult>& operands,
+  OperationArgument(IrContext* ir_context, const std::string& name);
+  explicit OperationArgument(OpInfo info) : info(info) {}
+  OperationArgument(const std::vector<OpResult>& operands,
+                    const AttributeMap& named_attr,
                     const std::vector<Type>& types,
-                    const AttributeMap& named_attr = {});
+                    OpInfo info,
+                    std::vector<std::unique_ptr<Region>>&& regions = {})
+      : inputs(operands),
+        attribute(named_attr),
+        output_types(types),
+        info(info),
+        regions(std::move(regions)) {}
 
   template <class InputIt>
   void addOperands(InputIt first, InputIt last);
@@ -51,31 +59,31 @@ struct OperationArgument {
 
   /// Add an attribute with the specified name.
   void addAttribute(const std::string& name, Attribute attr) {
-    attribute_[name] = attr;
+    this->attribute[name] = attr;
   }
   /// Add an array of named attributes.
   template <class InputIt>
   void addAttributes(InputIt first, InputIt last);
   /// Get the context held by this operation state.
-  IrContext* getContext() const { return info_.ir_context(); }
+  IrContext* getContext() const { return info.ir_context(); }
 };
 
 template <class InputIt>
 void OperationArgument::addOperands(InputIt first, InputIt last) {
   while (first != last) {
-    inputs_.emplace_back(*first++);
+    inputs.emplace_back(*first++);
   }
 }
 template <class InputIt>
 void OperationArgument::addTypes(InputIt first, InputIt last) {
   while (first != last) {
-    output_types_.emplace_back(*first++);
+    output_types.emplace_back(*first++);
   }
 }
 template <class InputIt>
 void OperationArgument::addAttributes(InputIt first, InputIt last) {
   while (first != last) {
-    attribute_[first->first] = first->second;
+    attribute[first->first] = first->second;
     ++first;
   }
 }
diff --git a/paddle/ir/core/region.cc b/paddle/ir/core/region.cc
new file mode 100644
index 0000000000000..905f497c0bc78
--- /dev/null
+++ b/paddle/ir/core/region.cc
@@ -0,0 +1,48 @@
+// Copyright (c) 2023 PaddlePaddle Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "paddle/ir/core/region.h"
+#include "paddle/ir/core/block.h"
+
+namespace ir {
+Region::~Region() { clear(); }
+
+void Region::push_back(Block *block) {
+  block->set_parent(this);
+  blocks_.push_back(block);
+}
+void Region::push_front(Block *block) {
+  block->set_parent(this);
+  blocks_.push_front(block);
+}
+
+Region::iterator Region::insert(const_iterator position, Block *block) {
+  block->set_parent(this);
+  return blocks_.insert(position, block);
+}
+void Region::TakeBody(Region &&other) {
+  clear();
+  blocks_.swap(other.blocks_);
+  for (auto &block : blocks_) {
+    block->set_parent(this);
+  }
+}
+
+void Region::clear() {
+  while (!empty()) {
+    delete blocks_.back();
+    blocks_.pop_back();
+  }
+}
+}  // namespace ir
diff --git a/paddle/ir/core/region.h b/paddle/ir/core/region.h
new file mode 100644
index 0000000000000..da84d970f1f72
--- /dev/null
+++ b/paddle/ir/core/region.h
@@ -0,0 +1,60 @@
+// Copyright (c) 2023 PaddlePaddle Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#pragma once
+
+#include <cstddef>
+#include <list>
+
+namespace ir {
+
+class Block;
+class Operation;
+
+class Region {
+ public:
+  using iterator = std::list<Block *>::iterator;
+  using reverse_iterator = std::list<Block *>::reverse_iterator;
+  using const_iterator = std::list<Block *>::const_iterator;
+  ~Region();
+  Region() = default;
+
+  bool empty() const { return blocks_.empty(); }
+  size_t size() const { return blocks_.size(); }
+
+  iterator begin() { return blocks_.begin(); }
+  iterator end() { return blocks_.end(); }
+  reverse_iterator rbegin() { return blocks_.rbegin(); }
+  reverse_iterator rend() { return blocks_.rend(); }
+
+  Block *back() const { return blocks_.back(); }
+  Block *front() const { return blocks_.front(); }
+  void push_back(Block *block);
+  void push_front(Block *block);
+  iterator insert(const_iterator position, Block *block);
+  void clear();
+
+  void TakeBody(Region &&other);
+
+ private:
+  Region(Region &) = delete;
+  Region &operator=(const Region &) = delete;
+  friend class Operation;
+  explicit Region(Operation *op) : parent_(op) {}
+
+ private:
+  Operation *parent_{nullptr};  // not owned
+  std::list<Block *> blocks_;   // owned
+};
+}  // namespace ir
diff --git a/test/cpp/ir/core/ir_op_test.cc b/test/cpp/ir/core/ir_op_test.cc
index 831a3f39b2196..af83acd5bfa87 100644
--- a/test/cpp/ir/core/ir_op_test.cc
+++ b/test/cpp/ir/core/ir_op_test.cc
@@ -14,12 +14,14 @@
 
 #include <gtest/gtest.h>
 
+#include "paddle/ir/core/block.h"
 #include "paddle/ir/core/builder.h"
 #include "paddle/ir/core/builtin_attribute.h"
 #include "paddle/ir/core/builtin_type.h"
 #include "paddle/ir/core/dialect.h"
 #include "paddle/ir/core/ir_context.h"
 #include "paddle/ir/core/op_base.h"
+#include "paddle/ir/core/region.h"
 
 /// \brief Define built-in Trait, derived from OpTraitBase.
 class ReadOnlyTrait : public ir::OpTraitBase<ReadOnlyTrait> {
@@ -175,9 +177,9 @@ TEST(op_test, op_test) {
   std::vector<ir::Type> op_output_types = {ir::Float32Type::get(ctx)};
   ir::Operation *op2 =
       ir::Operation::create(op_inputs,
-                            op_output_types,
                             CreateAttributeMap({"op2_attr1", "op2_attr2"},
                                                {"op2_attr1", "op2_attr2"}),
+                            op_output_types,
                             op2_info);
 
   ReadOnlyTrait trait = op2->dyn_cast<ReadOnlyTrait>();
@@ -188,3 +190,44 @@ TEST(op_test, op_test) {
   EXPECT_EQ(Op2.operation(), op2);
   op2->destroy();
 }
+
+TEST(op_test, region_test) {
+  // (1) Register Dialect, Operation1, Operation2 into IrContext.
+  ir::IrContext *ctx = ir::IrContext::Instance();
+  ir::Dialect *test_dialect = ctx->GetOrRegisterDialect<TestDialect>();
+  EXPECT_EQ(test_dialect != nullptr, true);
+
+  // (2) Get registered operations.
+  ir::OpInfo op1_info = ctx->GetRegisteredOpInfo(Operation1::name());
+  ir::OpInfo op2_info = ctx->GetRegisteredOpInfo(Operation2::name());
+
+  ir::Operation *op1 =
+      ir::Operation::create({},
+                            CreateAttributeMap({"op1_attr1", "op1_attr2"},
+                                               {"op1_attr1", "op1_attr2"}),
+                            {ir::Float32Type::get(ctx)},
+                            op1_info);
+  ir::Operation *op1_2 =
+      ir::Operation::create({},
+                            CreateAttributeMap({"op1_attr1", "op1_attr2"},
+                                               {"op1_attr1", "op1_attr2"}),
+                            {ir::Float32Type::get(ctx)},
+                            op1_info);
+
+  ir::OperationArgument argument(op2_info);
+  argument.attribute = CreateAttributeMap({"op2_attr1", "op2_attr2"},
+                                          {"op2_attr1", "op2_attr2"});
+  argument.output_types = {ir::Float32Type::get(ctx)};
+  argument.regions.emplace_back(std::make_unique<ir::Region>());
+  ir::Region *region = argument.regions.back().get();
+  EXPECT_EQ(region->empty(), true);
+
+  region->push_back(new ir::Block());
+  region->push_front(new ir::Block());
+  region->insert(region->begin(), new ir::Block());
+  ir::Block *block = region->front();
+  block->push_front(op1);
+  block->insert(block->begin(), op1_2);
+  ir::Operation *op2 = ir::Operation::create(std::move(argument));
+  op2->destroy();
+}
diff --git a/test/cpp/ir/core/ir_program_test.cc b/test/cpp/ir/core/ir_program_test.cc
index 34a24a0475d91..c16858ba1a219 100644
--- a/test/cpp/ir/core/ir_program_test.cc
+++ b/test/cpp/ir/core/ir_program_test.cc
@@ -91,7 +91,7 @@ TEST(program_test, program) {
   std::unordered_map<std::string, ir::Attribute> op1_attribute{
       {"parameter_name", ir::StrAttribute::get(ctx, "a")}};
   ir::Operation *op1 =
-      ir::Operation::create({}, {dense_tensor_dtype}, op1_attribute, op1_info);
+      ir::Operation::create({}, op1_attribute, {dense_tensor_dtype}, op1_info);
 
   program.InsertOp(op1);
 
@@ -123,7 +123,7 @@ TEST(program_test, program) {
   std::unordered_map<std::string, ir::Attribute> op2_attribute{
       {"parameter_name", ir::StrAttribute::get(ctx, "b")}};
   ir::Operation *op2 =
-      ir::Operation::create({}, {dense_tensor_dtype}, op2_attribute, op2_info);
+      ir::Operation::create({}, op2_attribute, {dense_tensor_dtype}, op2_info);
   program.InsertOp(op2);
 
   EXPECT_EQ(op2->GetResultByIndex(0).type().dialect().id(),
@@ -153,8 +153,8 @@ TEST(program_test, program) {
   std::unordered_map<std::string, ir::Attribute> op3_attribute;
   ir::Operation *op3 = ir::Operation::create(
       {op1->GetResultByIndex(0), op2->GetResultByIndex(0)},
-      {dense_tensor_dtype},
       op3_attribute,
+      {dense_tensor_dtype},
       op3_info);
   program.InsertOp(op3);
 
@@ -184,7 +184,7 @@ TEST(program_test, program) {
   std::unordered_map<std::string, ir::Attribute> op4_attribute{
       {"parameter_name", ir::StrAttribute::get(ctx, "c")}};
   ir::Operation *op4 = ir::Operation::create(
-      {op3->GetResultByIndex(0)}, {}, op4_attribute, op4_info);
+      {op3->GetResultByIndex(0)}, op4_attribute, {}, op4_info);
   program.InsertOp(op4);
 
   EXPECT_EQ(op4->GetOperandByIndex(0).impl()->source().type().dialect().id(),
@@ -230,7 +230,7 @@ TEST(program_test, slice_combine_test) {
   std::unordered_map<std::string, ir::Attribute> op1_attribute{
       {"parameter_name", ir::StrAttribute::get(ctx, "a")}};
   ir::Operation *op1 =
-      ir::Operation::create({}, {fp32_dtype}, op1_attribute, op1_info);
+      ir::Operation::create({}, op1_attribute, {fp32_dtype}, op1_info);
   program.InsertOp(op1);
 
   // (5) Def b = GetParameterOp("b")
@@ -239,7 +239,7 @@ TEST(program_test, slice_combine_test) {
   std::unordered_map<std::string, ir::Attribute> op2_attribute{
       {"parameter_name", ir::StrAttribute::get(ctx, "b")}};
   ir::Operation *op2 =
-      ir::Operation::create({}, {fp32_dtype}, op2_attribute, op2_info);
+      ir::Operation::create({}, op2_attribute, {fp32_dtype}, op2_info);
   program.InsertOp(op2);
 
   // (6) Def combine_op = CombineOp("a", "b")
@@ -249,8 +249,8 @@ TEST(program_test, slice_combine_test) {
       ir::VectorType::get(ctx, std::vector<ir::Type>({fp32_dtype, fp32_dtype}));
   ir::Operation *combine_op = ir::Operation::create(
       {op1->GetResultByIndex(0), op2->GetResultByIndex(0)},
-      {output_type},
       {},
+      {output_type},
       combine_op_info);
   program.InsertOp(combine_op);
 
@@ -260,8 +260,8 @@ TEST(program_test, slice_combine_test) {
   ir::Attribute index_attr = ir::Int32_tAttribute::get(ctx, 0);
   ir::Operation *slice_op =
       ir::Operation::create({combine_op->GetResultByIndex(0)},
-                            {fp32_dtype},
                             {{"index", index_attr}},
+                            {fp32_dtype},
                             slice_op_info);
   program.InsertOp(slice_op);
 
diff --git a/test/cpp/ir/core/ir_value_test.cc b/test/cpp/ir/core/ir_value_test.cc
index 9a7fbc1381055..28e340e52a527 100644
--- a/test/cpp/ir/core/ir_value_test.cc
+++ b/test/cpp/ir/core/ir_value_test.cc
@@ -40,8 +40,8 @@ TEST(value_test, value_test) {
   std::vector<ir::Type> op1_output_types = {ir::Float32Type::get(ctx)};
   ir::Operation *op1 =
       ir::Operation::create(op1_inputs,
-                            op1_output_types,
                             CreateAttributeMap("op1_name", "op1_attr"),
+                            op1_output_types,
                             nullptr);
   VLOG(0) << op1->print();
   // 2. Construct OP2: b = OP2();
@@ -49,8 +49,8 @@ TEST(value_test, value_test) {
   std::vector<ir::Type> op2_output_types = {ir::Float32Type::get(ctx)};
   ir::Operation *op2 =
       ir::Operation::create(op2_inputs,
-                            op2_output_types,
                             CreateAttributeMap("op2_name", "op2_attr"),
+                            op2_output_types,
                             nullptr);
   VLOG(0) << op2->print() << std::endl;
   // 3. Construct OP3: c = OP3(a, b);
@@ -59,8 +59,8 @@ TEST(value_test, value_test) {
   std::vector<ir::Type> op3_output_types = {ir::Float32Type::get(ctx)};
   ir::Operation *op3 =
       ir::Operation::create(op3_inputs,
-                            op3_output_types,
                             CreateAttributeMap("op3_name", "op3_attr"),
+                            op3_output_types,
                             nullptr);
   VLOG(0) << op3->print() << std::endl;
   // 4. Construct OP4: d, e, f, g, h, i, j = OP4(a, c);
@@ -72,8 +72,8 @@ TEST(value_test, value_test) {
   }
   ir::Operation *op4 =
       ir::Operation::create(op4_inputs,
-                            op4_output_types,
                             CreateAttributeMap("op4_name", "op4_attr"),
+                            op4_output_types,
                             nullptr);
   VLOG(0) << op4->print() << std::endl;
 
diff --git a/test/cpp/pass/pass_manager_test.cc b/test/cpp/pass/pass_manager_test.cc
index da46ffefa1d90..058f3600b032b 100644
--- a/test/cpp/pass/pass_manager_test.cc
+++ b/test/cpp/pass/pass_manager_test.cc
@@ -96,8 +96,8 @@ TEST(pass_manager_test, pass_manager_test) {
   std::vector<ir::Type> op_output_types = {ir::Float32Type::get(ctx)};
   ir::Operation *op =
       ir::Operation::create(op_inputs,
-                            op_output_types,
                             CreateAttributeMap(ctx, "op1_attr1", "op1_attr1"),
+                            op_output_types,
                             op_info);
 
   // (4) Test pass manager for op.