diff --git a/python/paddle/fluid/layers/nn.py b/python/paddle/fluid/layers/nn.py
index f79637c51a7a3395c97572736b69535fb05d94e9..68eb24ceb8c56ce333560bec4078bb7c17291b41 100644
--- a/python/paddle/fluid/layers/nn.py
+++ b/python/paddle/fluid/layers/nn.py
@@ -6559,7 +6559,6 @@ def sum(x, use_mkldnn=False):
 
     Returns:
         out (Variable): ${out_comment}
-
     """
 
     helper = LayerHelper('sum', **locals())