diff --git a/python/paddle/v2/fluid/tests/test_parallel_op.py b/python/paddle/v2/fluid/tests/test_parallel_op.py
index dde7206e4fd8dfc24b7685fb45771cccc7ec1651..2b51a1f50473d0728b8180772f42584797143b4e 100644
--- a/python/paddle/v2/fluid/tests/test_parallel_op.py
+++ b/python/paddle/v2/fluid/tests/test_parallel_op.py
@@ -147,7 +147,8 @@ class ParallelOpTest(BaseParallelForTest):
         self.run_test(
             callback=__network__,
             feed={
-                'img': numpy.random.random(size=(128, 784)).astype('float32')
+                'img':
+                numpy.random.random(size=(128 * 3, 784)).astype('float32')
             },
             fetch='fc1.w@GRAD')