diff --git a/api4cpp/readme.md b/api4cpp/readme.md
index b406393..c8724d2 100755
--- a/api4cpp/readme.md
+++ b/api4cpp/readme.md
@@ -34,3 +34,5 @@ ms vs: vs2015 or higher
 Onnxruntime: 1.6
 
 opencv :  3.x
+
+Mainly, it shoud link to library libopencv_imgcodecs 	libopencv_imgproc 	libopencv_core