diff --git a/python/paddle/fluid/layers/tensor.py b/python/paddle/fluid/layers/tensor.py
index a5c6344b9fb169f462142f9b7705edcc4bbf630e..0f098c370792605aecd83d4aa70bb2675aa0c481 100644
--- a/python/paddle/fluid/layers/tensor.py
+++ b/python/paddle/fluid/layers/tensor.py
@@ -164,7 +164,7 @@ def cast(x, dtype):
         x(Variable): An input N-D Tensor with data type bool, float16,
             float32, float64, int32, int64, uint8.
         dtype(np.dtype|core.VarDesc.VarType|str): Data type of the output:
-            bool, float15, float32, float64, int8, int32, int64, uint8.
+            bool, float16, float32, float64, int8, int32, int64, uint8.
 
     Returns:
         Variable: A Tensor with the same shape as input's.