diff --git a/doc/fluid/api_cn/tensor_cn/bmm_cn.rst b/doc/fluid/api_cn/tensor_cn/bmm_cn.rst
index 5cff0fb757048f6b2832a45f59b821b763810afb..87682f20f2ab0b790800e6e1a5a245f156d4a585 100644
--- a/doc/fluid/api_cn/tensor_cn/bmm_cn.rst
+++ b/doc/fluid/api_cn/tensor_cn/bmm_cn.rst
@@ -33,6 +33,7 @@ bmm
 .. code-block:: python
     
     import paddle
+    import numpy as np
 
     # In imperative mode:
     # size input1: (2, 2, 3) and input2: (2, 3, 2)