diff --git a/paddle/math/TensorAssign.h b/paddle/math/TensorAssign.h
index 0dc52a7dc27c96f9052e22bb2ef0ac75297a2f45..12a0244e8728ed5885237a4b9599aa5395102646 100644
--- a/paddle/math/TensorAssign.h
+++ b/paddle/math/TensorAssign.h
@@ -1,12 +1,16 @@
-/**
- * TensorAssign.h
- *
- * Author: hedaoyuan (hedaoyuan@baidu.com)
- * Created on: 2016-10-08
- *
- * Copyright (c) Baidu.com, Inc. All Rights Reserved
- *
- */
+/* Copyright (c) 2016 Baidu, Inc. All Rights Reserve.
+
+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
 
@@ -15,6 +19,10 @@
 
 namespace paddle {
 
+/**
+ * \brief Tensor Assign Expression(return by lazyAssign,
+ * and evaluated by AssignEvaluate) 
+ */
 template<typename LhsType, typename RhsType, class T>
 class TensorAssignOp {
 public:
@@ -91,7 +99,11 @@ void AssignGpuEvaluate2(const int height, const int width,
 }
 #endif
 
-// At least one assignment expression is required
+/**
+ * \brief Evaluate one or more TensorAssignOp objects.
+ *
+ * \note At least one assignment expression is required
+ */
 template <typename Assign, typename... AssignOp>
 void AssignEvaluate(Assign&& assign, AssignOp&& ... args) {
   const bool useGpu_ = assign.useGpu();
diff --git a/paddle/math/TensorExpression.h b/paddle/math/TensorExpression.h
index a98b6bb0d5e139507c808f079420f23909107f44..492b74d2195a55babe9d52908b47333eaee8f075 100644
--- a/paddle/math/TensorExpression.h
+++ b/paddle/math/TensorExpression.h
@@ -318,12 +318,19 @@ public:
     return condition(constant(p1), constant(p2));
   }
 
+  /**
+   * return a TensorConstant. A TensorConstant object hold a constant value.
+   */
   const TensorConstant<hppl::unary::constant<T>, const Derived, T>
   constant(T p) const {
     return TensorConstant<hppl::unary::constant<T>, const Derived, T>
       (hppl::unary::constant<T>(p), derived());
   }
 
+  /**
+   * return a TensorAssignOp, and use AssignEvaluate to evaluate one or more
+   * TensorAssignOp objects.
+   */
   template<typename ExpressionType>
   TensorAssignOp<Derived, ExpressionType, T>
   lazyAssign(const ExpressionType& expr) const {
diff --git a/paddle/math/tests/CMakeLists.txt b/paddle/math/tests/CMakeLists.txt
index 35cb9ee5784752543e211c90c721045d8a127a5d..633d6b4f1a86cea850039dda796f50eb8b6b3096 100644
--- a/paddle/math/tests/CMakeLists.txt
+++ b/paddle/math/tests/CMakeLists.txt
@@ -15,9 +15,9 @@ add_simple_unittest(test_perturbation)
 add_simple_unittest(test_CpuGpuVector)
 add_simple_unittest(test_Allocator)
 if(WITH_GPU)
-	CUDA_ADD_EXECUTABLE(test_Tensor test_Tensor.cu)
-	link_paddle_test(test_Tensor)
     if(COMPILER_SUPPORT_CXX11)
+    	CUDA_ADD_EXECUTABLE(test_Tensor test_Tensor.cu)
+		link_paddle_test(test_Tensor)
         CUDA_ADD_EXECUTABLE(test_lazyAssign test_lazyAssign.cu)
         link_paddle_test(test_lazyAssign)
     endif()
diff --git a/paddle/math/tests/TensorCheck.h b/paddle/math/tests/TensorCheck.h
index 8ffe1ea075940b48da5459f743b15d748e4abf3d..0d874edce08096381294f3d67c0f5ab9d0131dec 100644
--- a/paddle/math/tests/TensorCheck.h
+++ b/paddle/math/tests/TensorCheck.h
@@ -1,11 +1,16 @@
-/**
- * test_Tensor.cpp
- *
- * Author: hedaoyuan (hedaoyuan@baidu.com)
- * Created on: 2016-06-06
- *
- * Copyright (c) Baidu.com, Inc. All Rights Reserved
- */
+/* Copyright (c) 2016 Baidu, Inc. All Rights Reserve.
+
+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 <gtest/gtest.h>
 #include "paddle/math/Matrix.h"
diff --git a/paddle/math/tests/test_TrainingAlgorithm.cpp b/paddle/math/tests/test_TrainingAlgorithm.cpp
index 2c5807d9661187dede8deff676321a0d24ba3de2..301235d0e82bd0722711091d884fb25f8b5e4ae0 100644
--- a/paddle/math/tests/test_TrainingAlgorithm.cpp
+++ b/paddle/math/tests/test_TrainingAlgorithm.cpp
@@ -91,7 +91,11 @@ int VectorCheckErr(const VectorPtr& vector1, const VectorPtr& vector2) {
 typedef std::function<void(size_t size, bool useGpu)> testMatrixFunc;
 
 void testCase(testMatrixFunc matrixFunc) {
+#ifndef PADDLE_ONLY_CPU
   for (auto useGpu : {false, true}) {
+#else
+  for (auto useGpu : {false}) {
+#endif
     for (auto size : {1, 32, 64, 128, 512, 1024, 4096, 32768, 65536, 131072,
                        262144, 524288, 1048576, 2097152}) {
       LOG(INFO) << " size=" << size << " useGpu=" << useGpu;
diff --git a/paddle/math/tests/test_lazyAssign.cu b/paddle/math/tests/test_lazyAssign.cu
index 51cc874019dc91496ca4a69239085d0717095213..275510e55bab934cdf3b430fe626c0a0c74f2110 100644
--- a/paddle/math/tests/test_lazyAssign.cu
+++ b/paddle/math/tests/test_lazyAssign.cu
@@ -1,11 +1,16 @@
-/**
- * test_lazyAssign.cpp
- *
- * Author: hedaoyuan (hedaoyuan@baidu.com)
- * Created on: 2016-10-15
- *
- * Copyright (c) Baidu.com, Inc. All Rights Reserved
- */
+/* Copyright (c) 2016 Baidu, Inc. All Rights Reserve.
+
+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 <gtest/gtest.h>
 #include "paddle/math/Matrix.h"