diff --git a/core/model.py b/core/model.py
index e26cc7917c46f5edc1b81e9ecf253fdf618fe09b..9f9e3721185d761c37721079722ab809e7bc8c03 100755
--- a/core/model.py
+++ b/core/model.py
@@ -142,6 +142,7 @@ class Model(object):
     def train_net(self):
         input_data = self.input_data(is_infer=False)
         self._data_var = input_data
+        # if use dataset _data_loader not used
         self._data_loader = fluid.io.DataLoader.from_generator(
             feed_list=self._data_var,
             capacity=64,