diff --git a/mindspore/python/mindspore/ops/function/math_func.py b/mindspore/python/mindspore/ops/function/math_func.py
index 2962c084bd206e180e76c16173ef54d91b3d0ec9..a5796603301f72eb2f2647acea83f5e6122f8501 100644
--- a/mindspore/python/mindspore/ops/function/math_func.py
+++ b/mindspore/python/mindspore/ops/function/math_func.py
@@ -436,7 +436,7 @@ def exp2(x):
     return exp2_(tensor_2, x)
 
 
-def argmin(x, axis=-1, keepdims=False):
+def argmin(x, axis=None, keepdims=False):
     """
     Returns the indices of the minimum value of a tensor across the axis.