diff --git a/python/paddle_serving_server/server.py b/python/paddle_serving_server/server.py
index 9b56d6d79b942936cef81ad5da65c091f959dd97..ffa0cd5c7d03df9c2d579c53b73748c1304384b3 100755
--- a/python/paddle_serving_server/server.py
+++ b/python/paddle_serving_server/server.py
@@ -35,6 +35,7 @@ import numpy as np
 import grpc
 import sys
 import collections
+import subprocess
 
 from multiprocessing import Pool, Process
 from concurrent import futures