diff --git a/doc/design/cpp_data_feeding.md b/doc/design/cpp_data_feeding.md
index a122af8cb9002cbf126c3b2a22ebdfc9a78f9e93..22c2a925eb8c5e1dd8451e1d3cba261ce471ec51 100644
--- a/doc/design/cpp_data_feeding.md
+++ b/doc/design/cpp_data_feeding.md
@@ -20,7 +20,7 @@ class ReaderBase {
     PADDLE_ENFORCE(!shapes_.empty());
   }
   // Read the next batch of data. (A 'batch' can be only one instance)
-  // If the next batch doesn't exist, the 'out' will be an empty std::vector.
+  // If the next batch doesn't exist, the '*out' will be an empty std::vector.
   virtual void ReadNext(std::vector<LoDTensor>* out) = 0;
   
   // Reinitialize the reader and read the file from the begin.
diff --git a/paddle/fluid/operators/reader/create_batch_reader_op.cc b/paddle/fluid/operators/reader/create_batch_reader_op.cc
index 9559159e8298973d2c24d3ee820a8b2b42d80275..277f2856c07b3fec2113486539aec1d9139fae92 100644
--- a/paddle/fluid/operators/reader/create_batch_reader_op.cc
+++ b/paddle/fluid/operators/reader/create_batch_reader_op.cc
@@ -70,7 +70,7 @@ void BatchReader::ReadNext(std::vector<framework::LoDTensor>* out) {
   for (int i = 0; i < batch_size_; ++i) {
     buffer_.push_back(std::vector<framework::LoDTensor>());
     reader_->ReadNext(&buffer_.back());
-    if (buffer.back().empty()) {
+    if (buffer_.back().empty()) {
       buffer_.pop_back();
       break;
     }