diff --git a/python/paddle/fluid/metrics.py b/python/paddle/fluid/metrics.py
index 60d0e35d3a2ba0b6baec3e79cce1050e3ef8ab59..f409da90c14a42c86ddd5bc4a3093fbb7cba423a 100644
--- a/python/paddle/fluid/metrics.py
+++ b/python/paddle/fluid/metrics.py
@@ -610,8 +610,8 @@ class DetectionMAP(object):
 
         In the above example:
 
-        'cur_map_v' is the mAP of current mini-batch.
-        'accum_map_v' is the accumulative mAP of one pass.
+            'cur_map_v' is the mAP of current mini-batch.
+            'accum_map_v' is the accumulative mAP of one pass.
     """
 
     def __init__(self,