diff --git a/kcp/udp.go b/kcp/udp.go
new file mode 100755
index 0000000..1b5cb5c
--- /dev/null
+++ b/kcp/udp.go
@@ -0,0 +1,199 @@
+package kcp
+
+import (
+  "net"
+  "time"
+  "errors"
+)
+
+const (
+  SERVER_ADDR = "0.0.0.0:10878"
+  KDP_INTERVAL = 10 * time.Millisecond
+)
+
+const (
+  KDP_CLOSE = iota
+  KDP_READ
+  KDP_WRITE
+)
+
+func clock() uint32 {
+  Now := time.Now().UnixNano()
+  return uint32(Now / 1000000) & 0xFFFFFFFF
+}
+
+type cmd struct {
+  cmd  uint32
+  pipe chan *reply
+  args []interface{}
+}
+
+type reply struct {
+  err  error
+  rslt []interface{}
+}
+
+type kdp struct {
+  udp *net.UDPConn
+  kcp *KCP
+  
+  update bool
+  close bool
+  event chan *cmd
+}
+
+func (k *kdp) init(conv uint32, udp *net.UDPConn) {
+  k.udp = udp
+  k.kcp = NewKCP(conv, udp)
+  k.event = make(chan *cmd, 10)
+  go k.demon()
+}
+
+func (k *kdp) read() ([]byte, error) {
+  flow := make(chan *reply)
+  action := new(cmd)
+  action.cmd = KDP_READ
+  action.pipe = flow
+  
+  k.event <- action
+  rslt := <- flow
+  if rslt.err != nil {
+    return nil, rslt.err
+  } else {
+    data := rslt.rslt[0].([]byte)
+    return data, nil
+  }
+}
+
+func (k *kdp) write(data []byte) error  {
+  if data == nil || len(data) == 0 {
+    return nil
+  }
+  
+  flow := make(chan *reply)
+  action := new(cmd)
+  action.cmd = KDP_WRITE
+  action.pipe = flow
+  action.args = []interface{}{data}
+  k.event <- action
+  rslt := <- flow
+  if rslt.err != nil {
+    return rslt.err
+  } else {
+    return nil
+  }
+}
+
+func (k *kdp) execute(action *cmd) {
+  switch action.cmd {
+  case KDP_CLOSE:
+    k.execute_close(action)
+  case KDP_READ:
+    k.execute_read(action)
+  case KDP_WRITE:
+    k.execute_write(action)
+  default:
+    k.unknown_action(action)
+  }
+}
+
+func (k *kdp) execute_read(action *cmd) {
+  rslt := new(reply)
+  if data, err := k.kcp.receive(false); err != nil {
+    rslt.err = err
+  } else {
+    rslt.rslt = []interface{}{data}
+  }
+  
+}
+
+// need to write data here
+func (k *kdp) execute_write(action *cmd) {
+  rslt := new(reply)
+  if action.args == nil || len(action.args) < 1 {
+    rslt.err = errors.New("bad args")
+  } else if data, ok := action.args[0].([]byte); !ok {
+    rslt.err = errors.New("bad args")
+  } else {
+    rslt.err = k.kcp.send(data)
+  }
+  action.pipe <- rslt
+}
+
+// need to do nothing here
+func (k *kdp) execute_close(action *cmd) {
+}
+
+// just report error
+func (k *kdp) unknown_action(action *cmd) {
+  rslt := new(reply)
+  rslt.err = errors.New("unknown command")
+  go func() {action.pipe <- rslt}()
+}
+
+func (k *kdp) demon() {
+  trigger := time.NewTicker(KDP_INTERVAL)
+  var update_time uint32
+  for {
+    select {
+    case <- trigger.C:
+      current := clock()
+      if k.update || update_time <= current {
+        k.kcp.update(current)
+        update_time = k.kcp.check(current)
+      }
+    case action := <- k.event:
+      k.execute(action)
+      if k.close {
+        return
+      }
+    }
+  }
+}
+
+
+type Client struct {
+  udp *net.UDPConn
+}
+
+func Dial(raddr string) (*Client, error) {
+  client := new(Client)
+  if remote, err := net.ResolveUDPAddr("udp4", raddr); err != nil {
+    return nil, err
+  } else if conn, err := net.DialUDP("udp4", nil, remote); err != nil {
+    defer conn.Close()
+    return nil, err
+  } else {
+    client.udp = conn
+  }
+  go client.play()
+  return client, nil
+}
+
+// Waiting data from server and 
+func (client *Client) play() {
+  
+}
+
+type Server struct {
+  udp *net.UDPConn
+}
+
+func Listen(laddr string) (*Server, error) {
+  server := new(Server)
+  if local, err := net.ResolveUDPAddr("udp4", SERVER_ADDR); err != nil {
+    return nil, err
+  } else if conn, err := net.ListenUDP("udp4", local); err != nil {
+    defer conn.Close()
+    return nil, err
+  } else {
+    server.udp = conn
+  }
+  go server.play()
+  return server, nil
+}
+
+// Waiting data from client
+func (server *Server) play() {
+  
+}
\ No newline at end of file