diff --git a/demo/mnist/api_train.py b/demo/mnist/api_train.py
index 5d4ef90f10d3d4faeb43f61a8c20862c2f8dbbd1..b061cfb2b8f1faa7979093af19288475b99c57ff 100644
--- a/demo/mnist/api_train.py
+++ b/demo/mnist/api_train.py
@@ -30,7 +30,12 @@ def main():
     updater = api.ParameterUpdater.createLocalUpdater(opt_config)
     assert isinstance(updater, api.ParameterUpdater)
     updater.init(m)
-    updater.startPass()
+    m.start()
+
+    for _ in xrange(100):
+        updater.startPass()
+
+    m.finish()
 
 
 if __name__ == '__main__':
diff --git a/paddle/api/GradientMachine.cpp b/paddle/api/GradientMachine.cpp
index 297eaa19bb9981c7f07c90763d76494b7910af93..2cece2109795a986966d2decfdde27b2759e51cc 100644
--- a/paddle/api/GradientMachine.cpp
+++ b/paddle/api/GradientMachine.cpp
@@ -64,6 +64,10 @@ GradientMachine* GradientMachine::createByModelConfig(
   return GradientMachine::createFromPaddleModelPtr(confPtr, mode, types);
 }
 
+void GradientMachine::start() { m->machine->start(); }
+
+void GradientMachine::finish() { m->machine->finish(); }
+
 void GradientMachine::forward(const Arguments& inArgs,
                               Arguments* outArgs,
                               PassType passType) {
diff --git a/paddle/api/PaddleAPI.h b/paddle/api/PaddleAPI.h
index bd413eb1e9d9a945965bdf6767da82b4d631bbb5..c074325091dee95ab4a07e2f06e2abeb7a5c76bc 100644
--- a/paddle/api/PaddleAPI.h
+++ b/paddle/api/PaddleAPI.h
@@ -716,6 +716,13 @@ public:
       GradientMatchineCreateMode mode = CREATE_MODE_NORMAL,
       const std::vector<int>& parameterTypes = defaultParamTypes);
 
+  /**
+   * @brief finish
+   */
+  void finish();
+
+  void start();
+
   /**
    * The forward stage of GradientMachine.
    *
@@ -790,6 +797,8 @@ public:
 
   void startPass();
 
+  void finishPass();
+
 private:
   ParameterUpdaterPrivate* m;
 };
diff --git a/paddle/api/ParameterUpdater.cpp b/paddle/api/ParameterUpdater.cpp
index af5b746a7cd0825dcb6839b64e464228713efbd5..3b626c05071393740d198d9785879ea35d89647d 100644
--- a/paddle/api/ParameterUpdater.cpp
+++ b/paddle/api/ParameterUpdater.cpp
@@ -33,3 +33,5 @@ void ParameterUpdater::init(const GradientMachine &gm) {
 }
 
 void ParameterUpdater::startPass() { m->updater->startPass(); }
+
+void ParameterUpdater::finishPass() {}