diff --git a/agents/aliyun/fence_aliyun.py b/agents/aliyun/fence_aliyun.py
index ec7d2316..0f24b83e 100644
--- a/agents/aliyun/fence_aliyun.py
+++ b/agents/aliyun/fence_aliyun.py
@@ -1,146 +1,148 @@
 #!/usr/bin/python -tt
 
-import sys, re
-import logging
-import atexit
-import json
-sys.path.append("@FENCEAGENTSLIBDIR@")
-from fencing import *
-from fencing import fail, fail_usage, EC_TIMED_OUT, run_delay
-
-from aliyunsdkcore import client
-
-from aliyunsdkecs.request.v20140526.DescribeInstancesRequest import DescribeInstancesRequest
-from aliyunsdkecs.request.v20140526.StartInstanceRequest import StartInstanceRequest
-from aliyunsdkecs.request.v20140526.StopInstanceRequest import StopInstanceRequest
-from aliyunsdkecs.request.v20140526.RebootInstanceRequest import RebootInstanceRequest
-
+try:
+	import sys, re
+	import logging
+	import atexit
+	import json
+	sys.path.append("@FENCEAGENTSLIBDIR@")
+	from fencing import *
+	from fencing import fail, fail_usage, EC_TIMED_OUT, run_delay
+
+	from aliyunsdkcore import client
+
+	from aliyunsdkecs.request.v20140526.DescribeInstancesRequest import DescribeInstancesRequest
+	from aliyunsdkecs.request.v20140526.StartInstanceRequest import StartInstanceRequest
+	from aliyunsdkecs.request.v20140526.StopInstanceRequest import StopInstanceRequest
+	from aliyunsdkecs.request.v20140526.RebootInstanceRequest import RebootInstanceRequest
+except ImportError:
+	pass
 def _send_request(conn, request):
 	request.set_accept_format('json')
 	try:
 		response_str = conn.do_action_with_exception(request)
 		response_detail = json.loads(response_str)
 		return response_detail
 	except Exception as e:
 		fail_usage("Failed: _send_request failed")
 
 def start_instance(conn, instance_id):
 	request = StartInstanceRequest()
 	request.set_InstanceId(instance_id)
 	_send_request(conn, request)
 
 def stop_instance(conn, instance_id):
 	request = StopInstanceRequest()
 	request.set_InstanceId(instance_id)
 	request.set_ForceStop('true')
 	_send_request(conn, request)
 
 def reboot_instance(conn, instance_id):
 	request = RebootInstanceRequest()
 	request.set_InstanceId(instance_id)
 	request.set_ForceStop('true')
 	_send_request(conn, request)
 
 def get_status(conn, instance_id):
 	request = DescribeInstancesRequest()
 	request.set_InstanceIds(json.dumps([instance_id]))
 	response = _send_request(conn, request)
 	instance_status = None
 	if response is not None:
 		instance_list = response.get('Instances').get('Instance')
 		for item in instance_list:
 			instance_status = item.get('Status')
 	return instance_status
 
 def get_nodes_list(conn, options):
 	result = {}
 	request = DescribeInstancesRequest()
 	response = _send_request(conn, request)
 	instance_status = None
 	if response is not None:
 		instance_list = response.get('Instances').get('Instance')
 		for item in instance_list:
 			instance_id = item.get('InstanceId')
 			result[instance_id] = ("", None)
 	return result
 
 def get_power_status(conn, options):
 	state = get_status(conn, options["--plug"])
 	if state == "Running":
 		return "on"
 	elif state == "Stopped":
 		return "off"
 	else:
 		return "unknown"
 
 
 def set_power_status(conn, options):
 	if (options["--action"]=="off"):
 		stop_instance(conn, options["--plug"])
 	elif (options["--action"]=="on"):
 		start_instance(conn, options["--plug"])
 	elif (options["--action"]=="reboot"):
 		reboot_instance(conn, options["--plug"])
 
 
 def define_new_opts():
 	all_opt["region"] = {
 		"getopt" : "r:",
 		"longopt" : "region",
 		"help" : "-r, --region=[name]            Region, e.g. cn-hangzhou",
 		"shortdesc" : "Region.",
 		"required" : "0",
 		"order" : 2
 	}
 	all_opt["access_key"] = {
 		"getopt" : "a:",
 		"longopt" : "access-key",
 		"help" : "-a, --access-key=[name]         Access Key",
 		"shortdesc" : "Access Key.",
 		"required" : "0",
 		"order" : 3
 	}
 	all_opt["secret_key"] = {
 		"getopt" : "s:",
 		"longopt" : "secret-key",
 		"help" : "-s, --secret-key=[name]         Secret Key",
 		"shortdesc" : "Secret Key.",
 		"required" : "0",
 		"order" : 4
 	}
 
 # Main agent method
 def main():
 	conn = None
 
 	device_opt = ["port", "no_password", "region", "access_key", "secret_key"]
 
 	atexit.register(atexit_handler)
 
 	define_new_opts()
 
 	all_opt["power_timeout"]["default"] = "60"
 
 	options = check_input(device_opt, process_input(device_opt))
 
 	docs = {}
 	docs["shortdesc"] = "Fence agent for Aliyun (Aliyun Web Services)"
 	docs["longdesc"] = "fence_aliyun is an I/O Fencing agent for Aliyun"
 	docs["vendorurl"] = "http://www.aliyun.com"
 	show_docs(options, docs)
 
 	run_delay(options)
 
 	if "--region" in options and "--access-key" in options and "--secret-key" in options:  
 		region = options["--region"]
 		access_key = options["--access-key"]
 		secret_key = options["--secret-key"]
 		conn = client.AcsClient(access_key, secret_key, region)
 
 
 	# Operate the fencing device
 	result = fence_action(conn, options, set_power_status, get_power_status, get_nodes_list)
 	sys.exit(result)
 
 if __name__ == "__main__":
 	main()