diff --git a/trunk/src/app/srs_app_server.cpp b/trunk/src/app/srs_app_server.cpp
index 5d9fe37e07..06fb299b57 100644
--- a/trunk/src/app/srs_app_server.cpp
+++ b/trunk/src/app/srs_app_server.cpp
@@ -1650,6 +1650,7 @@ SrsApiServer::SrsApiServer()
     http_ = new SrsBufferListener(this, SrsListenerHttpApi);
     https_ = new SrsBufferListener(this, SrsListenerHttpApi);
     conn_manager_ = new SrsResourceManager("api");
+    lock_ = srs_mutex_new();
 }
 
 SrsApiServer::~SrsApiServer()
@@ -1658,6 +1659,7 @@ SrsApiServer::~SrsApiServer()
     srs_freep(http_);
     srs_freep(https_);
     srs_freep(conn_manager_);
+    srs_mutex_destroy(lock_);
 }
 
 srs_error_t SrsApiServer::initialize()
@@ -1973,15 +1975,21 @@ srs_error_t SrsApiServer::create_session(
     m.id = (uint64_t)SrsThreadMessageIDRtcCreateSession;
     m.ptr = (uint64_t)&s;
 
-    // We're initiator, write to initiator, read from responder.
-    // TODO: FIXME: Write important logs, and error response, and timeout?
-    if ((err = channel->initiator()->write(&m, sizeof(m), NULL)) != srs_success) {
-        return srs_error_wrap(err, "write");
-    }
+    if (true) {
+        // Process api request one by one.
+        // TODO: FIXME: The lock too big? Write log and error?
+        SrsLocker(lock_);
+
+        // We're initiator, write to initiator, read from responder.
+        // TODO: FIXME: Write important logs, and error response, and timeout?
+        if ((err = channel->initiator()->write(&m, sizeof(m), NULL)) != srs_success) {
+            return srs_error_wrap(err, "write");
+        }
 
-    // TODO: FIXME: Write important logs, and error response, and timeout?
-    if ((err = channel->responder()->read(&m, sizeof(m), NULL)) != srs_success) {
-        return srs_error_wrap(err, "read");
+        // TODO: FIXME: Write important logs, and error response, and timeout?
+        if ((err = channel->responder()->read(&m, sizeof(m), NULL)) != srs_success) {
+            return srs_error_wrap(err, "read");
+        }
     }
 
     // Covert to output params.
diff --git a/trunk/src/app/srs_app_server.hpp b/trunk/src/app/srs_app_server.hpp
index 8c1bcfa67c..f7063785d4 100644
--- a/trunk/src/app/srs_app_server.hpp
+++ b/trunk/src/app/srs_app_server.hpp
@@ -421,6 +421,9 @@ class SrsApiServer : public ISrsTcpMuxHandler, public ISrsResourceManager, publi
 private:
     // Key is stream url, value is hybrid thread entry.
     std::map<std::string, SrsThreadEntry*> hybrids_;
+private:
+    // To process api request one by one.
+    srs_mutex_t lock_;
 public:
     SrsApiServer();
     virtual ~SrsApiServer();