diff --git a/python/paddle/fluid/tests/unittests/test_recordio_reader.py b/python/paddle/fluid/tests/unittests/test_recordio_reader.py
index 2982cb8ceb50c31e98a8f272baf0db76e4e288c5..7c8e7f634fdd3ee3f056a95df774402a7c29e906 100644
--- a/python/paddle/fluid/tests/unittests/test_recordio_reader.py
+++ b/python/paddle/fluid/tests/unittests/test_recordio_reader.py
@@ -66,7 +66,6 @@ class TestRecordIO(unittest.TestCase):
             # train a pass
             batch_id = 0
             while True:
-                ex = None
                 try:
                     tmp, = exe.run(fetch_list=[avg_loss])
                 except fluid.core.EnforceNotMet as ex: