diff --git a/docs/developer_guides/chap04_message_stream.md b/docs/developer_guides/chap04_message_stream.md
index 0d9c65cb73..c238001d40 100644
--- a/docs/developer_guides/chap04_message_stream.md
+++ b/docs/developer_guides/chap04_message_stream.md
@@ -256,29 +256,6 @@ type RmsFactory struct {
 func (f *PmsFactory) NewMsgStream(ctx context.Context) (MsgStream, error)
 
 
-type PulsarTtMsgStream struct {
-	client			*pulsar.Client
-	repackFunc	RepackFunc
-	producers	 []*pulsar.Producer
-	consumers	 []*pulsar.Consumer
-	unmarshal	 *UnmarshalDispatcher
-	inputBuf		[]*TsMsg
-	unsolvedBuf []*TsMsg
-	msgPacks		[]*MsgPack
-}
-
-func (ms *PulsarTtMsgStream) Start() error
-func (ms *PulsarTtMsgStream) Close() error
-func (ms *PulsarTtMsgStream) AsProducer(channels []string)
-func (ms *PulsarTtMsgStream) AsConsumer(channels []string, subName string)
-func (ms *PulsarTtMsgStream) Produce(ctx context.Context, msgs *MsgPack) error
-func (ms *PulsarTtMsgStream) Broadcast(ctx context.Context, msgs *MsgPack) error
-func (ms *PulsarTtMsgStream) Consume() (*MsgPack, context.Context) //return messages in one time tick
-func (ms *PulsarTtMsgStream) Seek(mp *MsgPosition) error
-func (ms *PulsarTtMsgStream) SetRepackFunc(repackFunc RepackFunc)
-
-func NewPulsarTtMsgStream(ctx context.Context, pulsarAddr string, bufferSize int64) *PulsarTtMsgStream
-
 // RmqMsgStream
 
 type RmqMsgStream struct {