diff --git a/paddle/fluid/framework/operator.h b/paddle/fluid/framework/operator.h
index 87bb28c0c55efcf709e31ed3d43144bb528ce0f8..51de4c9dfb583b8e8a7fe8d92d5be07d32609c67 100644
--- a/paddle/fluid/framework/operator.h
+++ b/paddle/fluid/framework/operator.h
@@ -70,7 +70,7 @@ inline std::string GradVarName(const std::string& var_name) {
 }
 
 inline std::string OriginVarName(const std::string& grad_var_name) {
-  std::size_t pos = grad_var_name.find_last_of(kGradVarSuffix);
+  std::size_t pos = grad_var_name.rfind(kGradVarSuffix);
   if (pos == std::string::npos) {
     return grad_var_name;
   } else {
diff --git a/paddle/fluid/framework/operator_test.cc b/paddle/fluid/framework/operator_test.cc
index 1623dfca6f2e3575afc70f4feabb63d514f9c518..3bbbda6424ca110eabe31f232207c7562d4c8fc5 100644
--- a/paddle/fluid/framework/operator_test.cc
+++ b/paddle/fluid/framework/operator_test.cc
@@ -289,11 +289,29 @@ TEST(OpKernel, multi_inputs) {
   op->Run(scope, cpu_place);
 }
 
-TEST(Functions, all) {
+TEST(VarNameTest, all) {
   std::string var_name("X");
   std::string grad_var_name = paddle::framework::GradVarName(var_name);
-  ASSERT_EQ(grad_var_name.c_str(), "X@GRAD");
+  ASSERT_EQ(grad_var_name, "X@GRAD");
   std::string original_var_name =
       paddle::framework::OriginVarName(grad_var_name);
-  ASSERT_EQ(original_var_name.c_str(), "X");
+  ASSERT_EQ(original_var_name, "X");
+  original_var_name = paddle::framework::OriginVarName(original_var_name);
+  ASSERT_EQ(original_var_name, "X");
+
+  std::string var_name_2("XYZ");
+  grad_var_name = paddle::framework::GradVarName(var_name_2);
+  ASSERT_EQ(grad_var_name, "XYZ@GRAD");
+  original_var_name = paddle::framework::OriginVarName(grad_var_name);
+  ASSERT_EQ(original_var_name, "XYZ");
+  original_var_name = paddle::framework::OriginVarName(original_var_name);
+  ASSERT_EQ(original_var_name, "XYZ");
+
+  std::string var_name_3("");
+  grad_var_name = paddle::framework::GradVarName(var_name_3);
+  ASSERT_EQ(grad_var_name, "@GRAD");
+  original_var_name = paddle::framework::OriginVarName(grad_var_name);
+  ASSERT_EQ(original_var_name, "");
+  original_var_name = paddle::framework::OriginVarName(original_var_name);
+  ASSERT_EQ(original_var_name, "");
 }