diff --git a/shadowsocks/lru_cache.py b/shadowsocks/lru_cache.py
index 1313af5..bb28870 100644
--- a/shadowsocks/lru_cache.py
+++ b/shadowsocks/lru_cache.py
@@ -62,4 +62,4 @@ class LRUCache(collections.MutableMapping):
                     c += 1
             del self._time_to_keys[least]
         if c:
-            logging.debug('%d keys swept' % c)
+            logging.debug('%d keys swept' % c)
\ No newline at end of file
diff --git a/shadowsocks/server_pool.py b/shadowsocks/server_pool.py
index 286471c..31f54bd 100644
--- a/shadowsocks/server_pool.py
+++ b/shadowsocks/server_pool.py
@@ -48,7 +48,8 @@ class ServerPool(object):
         self.mgr = asyncmgr.ServerMgr()
         self.tcp_servers_pool = {}
         self.tcp_ipv6_servers_pool = {}
-        #self.udp_servers_pool = {}
+        self.udp_servers_pool = {}
+        self.udp_ipv6_servers_pool = {}
 
         self.loop = eventloop.EventLoop()
         thread.start_new_thread(ServerPool._loop, (self.loop, self.dns_resolver, self.mgr))
@@ -106,7 +107,9 @@ class ServerPool(object):
                     tcp_server = tcprelay.TCPRelay(a_config, self.dns_resolver, False)
                     tcp_server.add_to_loop(self.loop)
                     self.tcp_servers_pool.update({port: tcp_server})
-                    #udp_server = udprelay.UDPRelay(a_config, self.dns_resolver, False)
+                    udp_server = udprelay.UDPRelay(a_config, self.dns_resolver, False)
+                    udp_server.add_to_loop(self.loop)
+                    self.udp_servers_pool.update({port: udp_server})
                 except Exception, e:
                     logging.warn(e)
 
@@ -124,14 +127,16 @@ class ServerPool(object):
                     tcp_server = tcprelay.TCPRelay(a_config, self.dns_resolver, False)
                     tcp_server.add_to_loop(self.loop)
                     self.tcp_ipv6_servers_pool.update({port: tcp_server})
-                    #udp_server = udprelay.UDPRelay(a_config, self.dns_resolver, False)
+                    udp_server = udprelay.UDPRelay(a_config, self.dns_resolver, False)
+                    udp_server.add_to_loop(self.loop)
+                    self.udp_ipv6_servers_pool.update({port: udp_server})
                 except Exception, e:
                     logging.warn(e)
         return True
 
     def del_server(self, port):
         port = int(port)
-        logging.info("del server at %d" % int(port))
+        logging.info("del server at %d" % port)
         try:
             udpsock = socket(AF_INET, SOCK_DGRAM)
             udpsock.sendto('%s:%s:0:0' % (Config.MANAGE_PASS, port), (Config.MANAGE_BIND_IP, Config.MANAGE_PORT))
@@ -144,23 +149,26 @@ class ServerPool(object):
         port = int(port)
 
         if port not in self.tcp_servers_pool:
-            logging.info("stopped server at %s:%d already stop" % (self.config['server'], int(port)))
+            logging.info("stopped server at %s:%d already stop" % (self.config['server'], port))
         else:
-            logging.info("stopped server at %s:%d" % (self.config['server'], int(port)))
+            logging.info("stopped server at %s:%d" % (self.config['server'], port))
             try:
-                self.tcp_servers_pool[int(port)].destroy()
-                del self.tcp_servers_pool[int(port)]
-                #del self.udp_servers_pool[int(port)]
+                self.tcp_servers_pool[port].destroy()
+                del self.tcp_servers_pool[port]
+                self.udp_servers_pool[port].destroy()
+                del self.udp_servers_pool[port]
             except Exception, e:
                 logging.warn(e)
 
         if port not in self.tcp_ipv6_servers_pool:
-            logging.info("stopped server at %s:%d already stop" % (self.config['server_ipv6'], int(port)))
+            logging.info("stopped server at %s:%d already stop" % (self.config['server_ipv6'], port))
         else:
-            logging.info("stopped server at %s:%d" % (self.config['server_ipv6'], int(port)))
+            logging.info("stopped server at %s:%d" % (self.config['server_ipv6'], port))
             try:
-                self.tcp_ipv6_servers_pool[int(port)].destroy()
-                del self.tcp_ipv6_servers_pool[int(port)]
+                self.tcp_ipv6_servers_pool[port].destroy()
+                del self.tcp_ipv6_servers_pool[port]
+                self.udp_ipv6_servers_pool[port].destroy()
+                del self.udp_ipv6_servers_pool[port]
             except Exception, e:
                 logging.warn(e)
 
diff --git a/shadowsocks/udprelay.py b/shadowsocks/udprelay.py
index d7e3d4c..6302b8c 100644
--- a/shadowsocks/udprelay.py
+++ b/shadowsocks/udprelay.py
@@ -249,6 +249,17 @@ class UDPRelay(object):
         self._eventloop.add(server_socket,
                             eventloop.POLL_IN | eventloop.POLL_ERR)
 
+    def remove_to_loop(self):
+        self._eventloop.remove(self._server_socket)
+        self._eventloop.remove_handler(self._handle_events)
+
+    def destroy(self):
+        #destroy all conn and server conn
+        self.remove_to_loop()
+        self.close()
+        #GC
+        self._cache = None
+
     def _handle_events(self, events):
         for sock, fd, event in events:
             if sock == self._server_socket: