diff --git a/ppocr/postprocess/locality_aware_nms.py b/ppocr/postprocess/locality_aware_nms.py
index 53280cc13e..d305ef6818 100644
--- a/ppocr/postprocess/locality_aware_nms.py
+++ b/ppocr/postprocess/locality_aware_nms.py
@@ -1,5 +1,6 @@
 """
 Locality aware nms.
+This code is refered from: https://github.com/songdejia/EAST/blob/master/locality_aware_nms.py
 """
 
 import numpy as np