diff --git a/doc/fluid/api_cn/layers_cn/logical_not_cn.rst b/doc/fluid/api_cn/layers_cn/logical_not_cn.rst
index 2c604c7b62fdf09c93455ac909732df7fc65bbc9..40747ab04482ad36a95e3ed15dfc81434a3108a5 100644
--- a/doc/fluid/api_cn/layers_cn/logical_not_cn.rst
+++ b/doc/fluid/api_cn/layers_cn/logical_not_cn.rst
@@ -3,7 +3,7 @@
 logical_not
 -------------------------------
 
-.. py:function:: paddle.fluid.layers.logical_not(, out=None, name=None)
+.. py:function:: paddle.fluid.layers.logical_not(x, out=None, name=None)
 
 该OP逐元素的对 ``X`` LoDTensor/Tensor进行逻辑非运算