diff --git a/PaddleCV/yolov3/reader.py b/PaddleCV/yolov3/reader.py
index 8d9ec6a4e38c00fd9122d9b5af91e23cb6b08a97..6224c9ff13b83f280878c87a0cc0b8775464688f 100644
--- a/PaddleCV/yolov3/reader.py
+++ b/PaddleCV/yolov3/reader.py
@@ -303,6 +303,11 @@ def train(size=416,
 
     if not use_multiprocess_reader:
         return generator
+    else:
+        print("multiprocess is not fully compatible with Windows, "
+                "you can set --use_multiprocess=False if there are "
+                "errors incured by multiprocess")
+        print("multiprocess reader starting up, it takes a while...")
 
     def infinite_reader():
         while True:
diff --git a/PaddleCV/yolov3/train.py b/PaddleCV/yolov3/train.py
index 129940be1b81cfeaa7b91a1dc11849d7ee752cff..3a9418bb714478dcaa8305bef66e89fee291b983 100644
--- a/PaddleCV/yolov3/train.py
+++ b/PaddleCV/yolov3/train.py
@@ -35,6 +35,7 @@ import numpy as np
 import random
 import time
 import shutil
+import subprocess
 from utility import (parse_args, print_arguments, 
                      SmoothedValue, check_gpu)