diff --git a/demo/mnist/api_train.py b/demo/mnist/api_train.py
index ce75d79bebe3a86563021f98833316e0ebee77cd..e5a9075c8ecc0b640bc01e39468b0e4946246998 100644
--- a/demo/mnist/api_train.py
+++ b/demo/mnist/api_train.py
@@ -54,7 +54,7 @@ def input_order_converter(generator):
 
 
 def main():
-    api.initPaddle("-use_gpu=false", "-trainer_count=4")  # use 4 cpu cores
+    api.initPaddle("-use_gpu=true", "-trainer_count=4")  # use 4 cpu cores
     config = paddle.trainer.config_parser.parse_config(
         'simple_mnist_network.py', '')