diff --git a/python/paddle/v2/fluid/layers/control_flow.py b/python/paddle/v2/fluid/layers/control_flow.py
index 458ced460a0158c2cd2854cee3543ce8e43a7e53..08c52390e979b002d8d2b69a89c1e513aefeba76 100644
--- a/python/paddle/v2/fluid/layers/control_flow.py
+++ b/python/paddle/v2/fluid/layers/control_flow.py
@@ -429,7 +429,8 @@ def lod_rank_table(x, level=0):
     Args:
         x (Variable): Input variable, a LoDTensor based which to create the lod
             rank table.
-        level (int): Specify the LoD level.
+        level (int): Specify the LoD level, on which to create the lod rank
+            table.
 
     Returns:
         Variable: The created LoDRankTable object.