diff --git a/paddle-gpu-serving/client/bert_service/bert_service.py b/paddle-gpu-serving/client/bert_service/bert_service.py
index 5aa9331b2058259cb9eb1da8ea6eeba0b11c41f1..48343815ade2022f3dadaf6ddb79b0e9735ef0e2 100644
--- a/paddle-gpu-serving/client/bert_service/bert_service.py
+++ b/paddle-gpu-serving/client/bert_service/bert_service.py
@@ -73,7 +73,7 @@ class BertService():
             server_ip = server.split(':')[0]
             server_port = int(server.split(':')[1])
             client.connect((server_ip, server_port))
-            client.send('pending server')
+            client.send(b'pending server')
             response = client.recv(1024).decode()
 
             response_list = response.split('\t')