diff --git a/connection/connection.go b/connection/connection.go
index 8e90fcb..72b4467 100644
--- a/connection/connection.go
+++ b/connection/connection.go
@@ -25,14 +25,16 @@ type CallBack interface {
 
 // Connection TCP 连接
 type Connection struct {
-	fd        int
-	connected atomic.Bool
-	outBuffer *ringbuffer.RingBuffer // write buffer
-	inBuffer  *ringbuffer.RingBuffer // read buffer
-	callBack  CallBack
-	loop      *eventloop.EventLoop
-	peerAddr  string
-	ctx       interface{}
+	fd           int
+	connected    atomic.Bool
+	outBuffer    *ringbuffer.RingBuffer // write buffer
+	outBufferLen atomic.Int64
+	inBuffer     *ringbuffer.RingBuffer // read buffer
+	inBufferLen  atomic.Int64
+	callBack     CallBack
+	loop         *eventloop.EventLoop
+	peerAddr     string
+	ctx          interface{}
 	KeyValueContext
 
 	idleTime    time.Duration
@@ -129,6 +131,16 @@ func (c *Connection) ShutdownWrite() error {
 	return unix.Shutdown(c.fd, unix.SHUT_WR)
 }
 
+// ReadBufferLength read buffer 当前积压的数据长度
+func (c *Connection) ReadBufferLength() int64 {
+	return c.inBufferLen.Get()
+}
+
+// WriteBufferLength write buffer 当前积压的数据长度
+func (c *Connection) WriteBufferLength() int64 {
+	return c.outBufferLen.Get()
+}
+
 // HandleEvent 内部使用，event loop 回调
 func (c *Connection) HandleEvent(fd int, events poller.Event) {
 	if c.idleTime > 0 {
@@ -147,6 +159,9 @@ func (c *Connection) HandleEvent(fd int, events poller.Event) {
 	} else if events&poller.EventRead != 0 {
 		c.handleRead(fd)
 	}
+
+	c.inBufferLen.Swap(int64(c.inBuffer.Length()))
+	c.outBufferLen.Swap(int64(c.outBuffer.Length()))
 }
 
 func (c *Connection) handlerProtocol(buffer *ringbuffer.RingBuffer) []byte {
diff --git a/example/bufferlength/main.go b/example/bufferlength/main.go
new file mode 100644
index 0000000..5f19a26
--- /dev/null
+++ b/example/bufferlength/main.go
@@ -0,0 +1,106 @@
+package main
+
+import (
+	"container/list"
+	"log"
+	"sync"
+	"time"
+
+	"github.com/Allenxuxu/gev"
+	"github.com/Allenxuxu/gev/connection"
+)
+
+const clientsKey = "demo_push_message_key"
+
+// Server example
+type Server struct {
+	conn   *list.List
+	mu     sync.RWMutex
+	server *gev.Server
+}
+
+// New server
+func New(ip, port string) (*Server, error) {
+	var err error
+	s := new(Server)
+	s.conn = list.New()
+	s.server, err = gev.NewServer(s,
+		gev.Address(ip+":"+port))
+	if err != nil {
+		return nil, err
+	}
+
+	return s, nil
+}
+
+// Start server
+func (s *Server) Start() {
+	s.server.RunEvery(1*time.Second, s.RunPush)
+	s.server.Start()
+}
+
+// Stop server
+func (s *Server) Stop() {
+	s.server.Stop()
+}
+
+// RunPush push message
+func (s *Server) RunPush() {
+	var next *list.Element
+
+	s.mu.RLock()
+	defer s.mu.RUnlock()
+
+	for e := s.conn.Front(); e != nil; e = next {
+		next = e.Next()
+
+		c := e.Value.(*connection.Connection)
+		if c.WriteBufferLength() > 1024*10 {
+			log.Printf("write buffer length > 1024*10")
+			continue
+		}
+		_ = c.Send([]byte("hello\n"))
+	}
+}
+
+// OnConnect callback
+func (s *Server) OnConnect(c *connection.Connection) {
+	log.Println(" OnConnect ： ", c.PeerAddr())
+
+	s.mu.Lock()
+	e := s.conn.PushBack(c)
+	s.mu.Unlock()
+	c.Set(clientsKey, e)
+}
+
+// OnMessage callback
+func (s *Server) OnMessage(c *connection.Connection, ctx interface{}, data []byte) (out []byte) {
+	log.Printf("OnMessage, read buffer len %d, write buffer len %d \n", c.ReadBufferLength(), c.WriteBufferLength())
+
+	out = data
+	return
+}
+
+// OnClose callback
+func (s *Server) OnClose(c *connection.Connection) {
+	log.Println("OnClose")
+	v, ok := c.Get(clientsKey)
+	if !ok {
+		log.Println("OnClose : get key fail")
+		return
+	}
+
+	s.mu.Lock()
+	s.conn.Remove(v.(*list.Element))
+	s.mu.Unlock()
+}
+
+func main() {
+	s, err := New("", "1833")
+	if err != nil {
+		panic(err)
+	}
+	defer s.Stop()
+
+	s.Start()
+}