diff --git a/README.kr.rst b/README.kr.rst
index 6b69a10..aca7127 100644
--- a/README.kr.rst
+++ b/README.kr.rst
@@ -248,6 +248,7 @@ tomotopy의 Python3 예제 코드는 https://github.com/bab2min/tomotopy/blob/ma
     * `tomotopy.LDAModel.used_vocabs`, `tomotopy.LDAModel.used_vocab_freq`, `tomotopy.LDAModel.used_vocab_df` 등의 새로운 프로퍼티가 모델에 추가되었습니다.
     * 새로운 토픽 모델인 g-DMR(`tomotopy.GDMRModel`)가 추가되었습니다.
     * macOS에서 `tomotopy.label.FoRelevance`를 생성할 때 발생하던 문제가 해결되었습니다.
+    * `tomotopy.utils.Corpus.add_doc`로 `raw`가 없는 문헌을 생성한 뒤 토픽 모델에 입력할 시 발생하는 오류를 수정했습니다.
 
 * 0.7.1 (2020-05-08)
     * `tomotopy.HLDAModel`용으로 `tomotopy.Document.path`가 새로 추가되었습니다.
diff --git a/README.rst b/README.rst
index c0a555f..a9be20d 100644
--- a/README.rst
+++ b/README.rst
@@ -254,6 +254,7 @@ History
     * New properties including `tomotopy.LDAModel.used_vocabs`, `tomotopy.LDAModel.used_vocab_freq` and `tomotopy.LDAModel.used_vocab_df` were added into topic models.
     * A new g-DMR topic model(`tomotopy.GDMRModel`) was added.
     * An error at initializing `tomotopy.label.FoRelevance` in macOS was fixed.
+    * An error that occured when using `tomotopy.utils.Corpus` created without `raw` parameters was fixed.
 
 * 0.7.1 (2020-05-08)
     * `tomotopy.Document.path` was added for `tomotopy.HLDAModel`.
diff --git a/src/python/py_DMR.cpp b/src/python/py_DMR.cpp
index 4aa7401..d352d7f 100644
--- a/src/python/py_DMR.cpp
+++ b/src/python/py_DMR.cpp
@@ -90,14 +90,25 @@ static PyObject* DMR_addDoc_(TopicModelObject* self, PyObject* args, PyObject *k
 		auto* inst = static_cast<tomoto::IDMRModel*>(self->inst);
 		string raw;
 		if (argRaw) raw = argRaw;
+		if (argRaw && (!argStartPos || !argLength))
+		{
+			throw runtime_error{ "`start_pos` and `length` must be given when `raw` is given." };
+		}
+
+		vector<tomoto::Vid> words;
+		vector<uint32_t> startPos;
+		vector<uint16_t> length;
 
 		py::UniqueObj iter = PyObject_GetIter(argWords);
-		vector<tomoto::Vid> words = py::makeIterToVector<tomoto::Vid>(iter);
-		iter = PyObject_GetIter(argStartPos);
-		vector<uint32_t> startPos = py::makeIterToVector<uint32_t>(iter);
-		iter = PyObject_GetIter(argLength);
-		vector<uint16_t> length = py::makeIterToVector<uint16_t>(iter);
-		char2Byte(raw, startPos, length);
+		words = py::makeIterToVector<tomoto::Vid>(iter);
+		if (argStartPos)
+		{
+			iter = PyObject_GetIter(argStartPos);
+			startPos = py::makeIterToVector<uint32_t>(iter);
+			iter = PyObject_GetIter(argLength);
+			length = py::makeIterToVector<uint16_t>(iter);
+			char2Byte(raw, startPos, length);
+		}
 		auto ret = inst->addDoc(raw, words, startPos, length, { string{metadata} });
 		return py::buildPyValue(ret);
 	}
diff --git a/src/python/py_DT.cpp b/src/python/py_DT.cpp
index 0d39dfe..8b487da 100644
--- a/src/python/py_DT.cpp
+++ b/src/python/py_DT.cpp
@@ -97,14 +97,25 @@ static PyObject* DT_addDoc_(TopicModelObject* self, PyObject* args, PyObject *kw
 		auto* inst = static_cast<tomoto::IDTModel*>(self->inst);
 		string raw;
 		if (argRaw) raw = argRaw;
+		if (argRaw && (!argStartPos || !argLength))
+		{
+			throw runtime_error{ "`start_pos` and `length` must be given when `raw` is given." };
+		}
+
+		vector<tomoto::Vid> words;
+		vector<uint32_t> startPos;
+		vector<uint16_t> length;
 
 		py::UniqueObj iter = PyObject_GetIter(argWords);
-		vector<tomoto::Vid> words = py::makeIterToVector<tomoto::Vid>(iter);
-		iter = PyObject_GetIter(argStartPos);
-		vector<uint32_t> startPos = py::makeIterToVector<uint32_t>(iter);
-		iter = PyObject_GetIter(argLength);
-		vector<uint16_t> length = py::makeIterToVector<uint16_t>(iter);
-		char2Byte(raw, startPos, length);
+		words = py::makeIterToVector<tomoto::Vid>(iter);
+		if (argStartPos)
+		{
+			iter = PyObject_GetIter(argStartPos);
+			startPos = py::makeIterToVector<uint32_t>(iter);
+			iter = PyObject_GetIter(argLength);
+			length = py::makeIterToVector<uint16_t>(iter);
+			char2Byte(raw, startPos, length);
+		}
 		auto ret = inst->addDoc(raw, words, startPos, length, timepoint);
 		return py::buildPyValue(ret);
 	}
diff --git a/src/python/py_GDMR.cpp b/src/python/py_GDMR.cpp
index b44ba8b..43369b0 100644
--- a/src/python/py_GDMR.cpp
+++ b/src/python/py_GDMR.cpp
@@ -129,14 +129,25 @@ static PyObject* GDMR_addDoc_(TopicModelObject* self, PyObject* args, PyObject *
 		auto* inst = static_cast<tomoto::IGDMRModel*>(self->inst);
 		string raw;
 		if (argRaw) raw = argRaw;
+		if (argRaw && (!argStartPos || !argLength))
+		{
+			throw runtime_error{ "`start_pos` and `length` must be given when `raw` is given." };
+		}
+
+		vector<tomoto::Vid> words;
+		vector<uint32_t> startPos;
+		vector<uint16_t> length;
 
 		py::UniqueObj iter = PyObject_GetIter(argWords), iterMetadata;
-		vector<tomoto::Vid> words = py::makeIterToVector<tomoto::Vid>(iter);
-		iter = PyObject_GetIter(argStartPos);
-		vector<uint32_t> startPos = py::makeIterToVector<uint32_t>(iter);
-		iter = PyObject_GetIter(argLength);
-		vector<uint16_t> length = py::makeIterToVector<uint16_t>(iter);
-		char2Byte(raw, startPos, length);
+		words = py::makeIterToVector<tomoto::Vid>(iter);
+		if (argStartPos)
+		{
+			iter = PyObject_GetIter(argStartPos);
+			startPos = py::makeIterToVector<uint32_t>(iter);
+			iter = PyObject_GetIter(argLength);
+			length = py::makeIterToVector<uint16_t>(iter);
+			char2Byte(raw, startPos, length);
+		}
 
 		if (!argMetadata || !(iterMetadata = PyObject_GetIter(argMetadata)))
 		{
diff --git a/src/python/py_LDA.cpp b/src/python/py_LDA.cpp
index e70abd8..a10ffbd 100644
--- a/src/python/py_LDA.cpp
+++ b/src/python/py_LDA.cpp
@@ -92,14 +92,25 @@ static PyObject* LDA_addDoc_(TopicModelObject* self, PyObject* args, PyObject *k
 		auto* inst = static_cast<tomoto::ILDAModel*>(self->inst);
 		string raw;
 		if (argRaw) raw = argRaw;
+		if (argRaw && (!argStartPos || !argLength))
+		{
+			throw runtime_error{ "`start_pos` and `length` must be given when `raw` is given." };
+		}
+
+		vector<tomoto::Vid> words;
+		vector<uint32_t> startPos;
+		vector<uint16_t> length;
 
 		py::UniqueObj iter = PyObject_GetIter(argWords);
-		vector<tomoto::Vid> words = py::makeIterToVector<tomoto::Vid>(iter);
-		iter = PyObject_GetIter(argStartPos);
-		vector<uint32_t> startPos = py::makeIterToVector<uint32_t>(iter);
-		iter = PyObject_GetIter(argLength);
-		vector<uint16_t> length = py::makeIterToVector<uint16_t>(iter);
-		char2Byte(raw, startPos, length);
+		words = py::makeIterToVector<tomoto::Vid>(iter);
+		if (argStartPos)
+		{
+			iter = PyObject_GetIter(argStartPos);
+			startPos = py::makeIterToVector<uint32_t>(iter);
+			iter = PyObject_GetIter(argLength);
+			length = py::makeIterToVector<uint16_t>(iter);
+			char2Byte(raw, startPos, length);
+		}
 		auto ret = inst->addDoc(raw, words, startPos, length);
 		return py::buildPyValue(ret);
 	}
diff --git a/src/python/py_LLDA.cpp b/src/python/py_LLDA.cpp
index 0b10d99..f0bb98e 100644
--- a/src/python/py_LLDA.cpp
+++ b/src/python/py_LLDA.cpp
@@ -99,14 +99,26 @@ static PyObject* LLDA_addDoc_(TopicModelObject* self, PyObject* args, PyObject *
 		auto* inst = static_cast<tomoto::ILLDAModel*>(self->inst);
 		string raw;
 		if (argRaw) raw = argRaw;
+		if (argRaw && (!argStartPos || !argLength))
+		{
+			throw runtime_error{ "`start_pos` and `length` must be given when `raw` is given." };
+		}
+
+		vector<tomoto::Vid> words;
+		vector<uint32_t> startPos;
+		vector<uint16_t> length;
 
 		py::UniqueObj iter = PyObject_GetIter(argWords);
-		vector<tomoto::Vid> words = py::makeIterToVector<tomoto::Vid>(iter);
-		iter = PyObject_GetIter(argStartPos);
-		vector<uint32_t> startPos = py::makeIterToVector<uint32_t>(iter);
-		iter = PyObject_GetIter(argLength);
-		vector<uint16_t> length = py::makeIterToVector<uint16_t>(iter);
-		char2Byte(raw, startPos, length);
+		words = py::makeIterToVector<tomoto::Vid>(iter);
+		if (argStartPos)
+		{
+			iter = PyObject_GetIter(argStartPos);
+			startPos = py::makeIterToVector<uint32_t>(iter);
+			iter = PyObject_GetIter(argLength);
+			length = py::makeIterToVector<uint16_t>(iter);
+			char2Byte(raw, startPos, length);
+		}
+
 		vector<string> labels;
 		if (argLabels)
 		{
diff --git a/src/python/py_MGLDA.cpp b/src/python/py_MGLDA.cpp
index 06f5d84..80ea3f4 100644
--- a/src/python/py_MGLDA.cpp
+++ b/src/python/py_MGLDA.cpp
@@ -93,14 +93,25 @@ static PyObject* MGLDA_addDoc_(TopicModelObject* self, PyObject* args, PyObject
 		auto* inst = static_cast<tomoto::IMGLDAModel*>(self->inst);
 		string raw;
 		if (argRaw) raw = argRaw;
+		if (argRaw && (!argStartPos || !argLength))
+		{
+			throw runtime_error{ "`start_pos` and `length` must be given when `raw` is given." };
+		}
+
+		vector<tomoto::Vid> words;
+		vector<uint32_t> startPos;
+		vector<uint16_t> length;
 
 		py::UniqueObj iter = PyObject_GetIter(argWords);
-		vector<tomoto::Vid> words = py::makeIterToVector<tomoto::Vid>(iter);
-		iter = PyObject_GetIter(argStartPos);
-		vector<uint32_t> startPos = py::makeIterToVector<uint32_t>(iter);
-		iter = PyObject_GetIter(argLength);
-		vector<uint16_t> length = py::makeIterToVector<uint16_t>(iter);
-		char2Byte(raw, startPos, length);
+		words = py::makeIterToVector<tomoto::Vid>(iter);
+		if (argStartPos)
+		{
+			iter = PyObject_GetIter(argStartPos);
+			startPos = py::makeIterToVector<uint32_t>(iter);
+			iter = PyObject_GetIter(argLength);
+			length = py::makeIterToVector<uint16_t>(iter);
+			char2Byte(raw, startPos, length);
+		}
 		
 		auto ret = inst->addDoc(raw, words, startPos, length, delimiter);
 		return py::buildPyValue(ret);
diff --git a/src/python/py_PLDA.cpp b/src/python/py_PLDA.cpp
index 0a94864..34a6cff 100644
--- a/src/python/py_PLDA.cpp
+++ b/src/python/py_PLDA.cpp
@@ -100,14 +100,26 @@ static PyObject* PLDA_addDoc_(TopicModelObject* self, PyObject* args, PyObject *
 		auto* inst = static_cast<tomoto::IPLDAModel*>(self->inst);
 		string raw;
 		if (argRaw) raw = argRaw;
+		if (argRaw && (!argStartPos || !argLength))
+		{
+			throw runtime_error{ "`start_pos` and `length` must be given when `raw` is given." };
+		}
+
+		vector<tomoto::Vid> words;
+		vector<uint32_t> startPos;
+		vector<uint16_t> length;
 
 		py::UniqueObj iter = PyObject_GetIter(argWords);
-		vector<tomoto::Vid> words = py::makeIterToVector<tomoto::Vid>(iter);
-		iter = PyObject_GetIter(argStartPos);
-		vector<uint32_t> startPos = py::makeIterToVector<uint32_t>(iter);
-		iter = PyObject_GetIter(argLength);
-		vector<uint16_t> length = py::makeIterToVector<uint16_t>(iter);
-		char2Byte(raw, startPos, length);
+		words = py::makeIterToVector<tomoto::Vid>(iter);
+		if (argStartPos)
+		{
+			iter = PyObject_GetIter(argStartPos);
+			startPos = py::makeIterToVector<uint32_t>(iter);
+			iter = PyObject_GetIter(argLength);
+			length = py::makeIterToVector<uint16_t>(iter);
+			char2Byte(raw, startPos, length);
+		}
+
 		vector<string> labels;
 		if (argLabels)
 		{
diff --git a/src/python/py_SLDA.cpp b/src/python/py_SLDA.cpp
index ede17b3..c5363f9 100644
--- a/src/python/py_SLDA.cpp
+++ b/src/python/py_SLDA.cpp
@@ -169,14 +169,26 @@ static PyObject* SLDA_addDoc_(TopicModelObject* self, PyObject* args, PyObject *
 		auto* inst = static_cast<tomoto::ISLDAModel*>(self->inst);
 		string raw;
 		if (argRaw) raw = argRaw;
+		if (argRaw && (!argStartPos || !argLength))
+		{
+			throw runtime_error{ "`start_pos` and `length` must be given when `raw` is given." };
+		}
+
+		vector<tomoto::Vid> words;
+		vector<uint32_t> startPos;
+		vector<uint16_t> length;
 
 		py::UniqueObj iter = PyObject_GetIter(argWords);
-		vector<tomoto::Vid> words = py::makeIterToVector<tomoto::Vid>(iter);
-		iter = PyObject_GetIter(argStartPos);
-		vector<uint32_t> startPos = py::makeIterToVector<uint32_t>(iter);
-		iter = PyObject_GetIter(argLength);
-		vector<uint16_t> length = py::makeIterToVector<uint16_t>(iter);
-		char2Byte(raw, startPos, length);
+		words = py::makeIterToVector<tomoto::Vid>(iter);
+		if (argStartPos)
+		{
+			iter = PyObject_GetIter(argStartPos);
+			startPos = py::makeIterToVector<uint32_t>(iter);
+			iter = PyObject_GetIter(argLength);
+			length = py::makeIterToVector<uint16_t>(iter);
+			char2Byte(raw, startPos, length);
+		}
+
 		vector<tomoto::Float> ys;
 		if (argY)
 		{
diff --git a/tomotopy/documentation.kr.rst b/tomotopy/documentation.kr.rst
index ba0f8d1..40c81f1 100644
--- a/tomotopy/documentation.kr.rst
+++ b/tomotopy/documentation.kr.rst
@@ -287,6 +287,7 @@ tomotopy의 Python3 예제 코드는 https://github.com/bab2min/tomotopy/blob/ma
     * `tomotopy.LDAModel.used_vocabs`, `tomotopy.LDAModel.used_vocab_freq`, `tomotopy.LDAModel.used_vocab_df` 등의 새로운 프로퍼티가 모델에 추가되었습니다.
     * 새로운 토픽 모델인 g-DMR(`tomotopy.GDMRModel`)가 추가되었습니다.
     * macOS에서 `tomotopy.label.FoRelevance`를 생성할 때 발생하던 문제가 해결되었습니다.
+    * `tomotopy.utils.Corpus.add_doc`로 `raw`가 없는 문헌을 생성한 뒤 토픽 모델에 입력할 시 발생하는 오류를 수정했습니다.
 
 * 0.7.1 (2020-05-08)
     * `tomotopy.HLDAModel`용으로 `tomotopy.Document.path`가 새로 추가되었습니다.
diff --git a/tomotopy/documentation.rst b/tomotopy/documentation.rst
index 2212b98..17801e9 100644
--- a/tomotopy/documentation.rst
+++ b/tomotopy/documentation.rst
@@ -290,6 +290,7 @@ History
     * New properties including `tomotopy.LDAModel.used_vocabs`, `tomotopy.LDAModel.used_vocab_freq` and `tomotopy.LDAModel.used_vocab_df` were added into topic models.
     * A new g-DMR topic model(`tomotopy.GDMRModel`) was added.
     * An error at initializing `tomotopy.label.FoRelevance` in macOS was fixed.
+    * An error that occured when using `tomotopy.utils.Corpus` created without `raw` parameters was fixed.
 
 * 0.7.1 (2020-05-08)
     * `tomotopy.Document.path` was added for `tomotopy.HLDAModel`.