diff --git a/paddle/gserver/tests/MKLDNNTester.cpp b/paddle/gserver/tests/MKLDNNTester.cpp
index d20215571dac807054bca4cc0ff88460515bb457..de1635be2af37cd0ba49010199a417090865b0e4 100644
--- a/paddle/gserver/tests/MKLDNNTester.cpp
+++ b/paddle/gserver/tests/MKLDNNTester.cpp
@@ -345,10 +345,10 @@ void MKLDNNTester::run(const TestConfig& dnn,
     return;
   }
 
-  // After run some iters, the mkldnn weight has been stored in dnnLayer
-  // and we can also get the mkldnn weight paramter header format
-  // Weight param should always be index 0 (and bias index 1).
-  // TODO(TJ): should also considerate mean and var format when batchnorm ready
+  // After run some iterations, the mkldnn weight has been stored in dnnLayer
+  // and we can also get the mkldnn weight parameter header format.
+  // Weight parameter should always be index 0 (and bias index 1).
+  // TODO(TJ): should also consider mean and var format when batchnorm ready
   int dnnWgtFmt = parameters_[DNN][0]->getHeaderFormat();
   int refWgtFmt = parameters_[REF][0]->getHeaderFormat();
   if (dnnWgtFmt == refWgtFmt) {
diff --git a/paddle/parameter/Parameter.h b/paddle/parameter/Parameter.h
index cffd3aa92e30ba66cd29f66fec8febb741bc5e85..e31cbc3dee6c57851c241e117dbbd9b701db9d2c 100644
--- a/paddle/parameter/Parameter.h
+++ b/paddle/parameter/Parameter.h
@@ -35,9 +35,17 @@ limitations under the License. */
 namespace paddle {
 
 typedef enum {
-  PARAM_FORMAT_ORIGINAL = 0,  // the paddle original basic format
-  PARAM_FORMAT_MKLDNN_OI,     // the mkldnn format oi
-  PARAM_FORMAT_ITEMS,         // the total format items numbers
+  /// The paddle original basic format
+  PARAM_FORMAT_ORIGINAL = 0,
+
+  /// See mkldnn_memory_format_t in
+  /// https://github.com/01org/mkl-dnn/blob/master/include/mkldnn_types.h
+  /// for a detailed description.
+  /// 2D weights tensor in the format (output channels, input channels).
+  PARAM_FORMAT_MKLDNN_OI,
+
+  /// The total format items numbers
+  PARAM_FORMAT_ITEMS,
 } PARAM_FORMAT;
 
 class SparsePrefetchRowCpuMatrix;
@@ -256,19 +264,19 @@ public:
   };
 
   /**
-   * @brief Is the header supported
+   * @brief Is the header format supported.
    */
   static bool isHeaderFormatSupported(int32_t fmt) {
     return fmt < PARAM_FORMAT_ITEMS;
   }
 
   /**
-   * @brief Get the format in header
+   * @brief Get the format in header.
    */
   int getHeaderFormat() { return headerFormat_; }
 
   /**
-   * @brief Set the format in header
+   * @brief Set the format in header.
    */
   void setHeaderFormat(int32_t fmt) { headerFormat_ = fmt; }
 
@@ -343,7 +351,7 @@ protected:
   bool updated_;
   SparseFormat format_;
 
-  // The header format for saving or loading param
+  /// The header format for saving or loading param
   int32_t headerFormat_;
 
   std::vector<std::shared_ptr<IParameterUpdaterHook>> updaterHooks_;