diff --git a/python/paddle/v2/trainer.py b/python/paddle/v2/trainer.py
index 07cf8aa13cb2fb2407349fe6224df53dd9502ef4..6719a268270da7bacd1b77cf8848e4a1591a7b79 100644
--- a/python/paddle/v2/trainer.py
+++ b/python/paddle/v2/trainer.py
@@ -108,9 +108,6 @@ class SGD(ITrainer):
             pass_evaluator.start()
             updater.startPass()
             for batch_id, data_batch in enumerate(reader()):
-                pass_type = updater.startBatch(len(data_batch))
-                self.__gradient_machine__.forwardBackward(
-                    feeder(data_batch), out_args, pass_type)
                 batch_evaluator.start()
                 event_handler(
                     v2_event.BeginIteration(