diff --git a/ledis/ledis.go b/ledis/ledis.go
index 0cf108a..3afa0f5 100644
--- a/ledis/ledis.go
+++ b/ledis/ledis.go
@@ -4,6 +4,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"github.com/siddontang/go-leveldb/leveldb"
+	"github.com/siddontang/go-log/log"
 	"path"
 	"sync"
 )
@@ -132,3 +133,13 @@ func (l *Ledis) Select(index int) (*DB, error) {
 
 	return l.dbs[index], nil
 }
+
+func (l *Ledis) FlushAll() error {
+	for index, db := range l.dbs {
+		if _, err := db.FlushAll(); err != nil {
+			log.Error("flush db %d error %s", index, err.Error())
+		}
+	}
+
+	return nil
+}
diff --git a/server/app.go b/server/app.go
index cf76049..1b745b6 100644
--- a/server/app.go
+++ b/server/app.go
@@ -16,9 +16,10 @@ type App struct {
 
 	closed bool
 
-	slaveMode bool
-
 	quit chan struct{}
+
+	//for slave replication
+	master masterInfo
 }
 
 func NewApp(cfg *Config) (*App, error) {
@@ -50,12 +51,6 @@ func NewApp(cfg *Config) (*App, error) {
 		return nil, err
 	}
 
-	app.slaveMode = false
-
-	if len(app.cfg.SlaveOf) > 0 {
-		app.slaveMode = true
-	}
-
 	if app.ldb, err = ledis.OpenWithConfig(&cfg.DB); err != nil {
 		return nil, err
 	}
@@ -78,7 +73,7 @@ func (app *App) Close() {
 }
 
 func (app *App) Run() {
-	if app.slaveMode {
+	if len(app.cfg.SlaveOf) > 0 {
 		app.runReplication()
 	}
 
diff --git a/server/cmd_replication.go b/server/cmd_replication.go
index 634d57f..8588877 100644
--- a/server/cmd_replication.go
+++ b/server/cmd_replication.go
@@ -1,16 +1,33 @@
 package server
 
+import (
+	"fmt"
+	"github.com/siddontang/ledisdb/ledis"
+	"strconv"
+	"strings"
+)
+
 func slaveofCommand(c *client) error {
-	if len(c.args) > 1 {
+	args := c.args
+
+	if len(args) != 2 {
 		return ErrCmdParams
 	}
 
-	master := ""
-	if len(c.args) == 1 {
-		master = string(c.args[0])
+	masterAddr := ""
+
+	if strings.ToLower(ledis.String(args[0])) == "no" &&
+		strings.ToLower(ledis.String(args[1])) == "one" {
+		//stop replication, use master = ""
+	} else {
+		if _, err := strconv.ParseInt(ledis.String(args[1]), 10, 16); err != nil {
+			return err
+		}
+
+		masterAddr = fmt.Sprintf("%s:%s", args[0], args[1])
 	}
 
-	if err := c.app.slaveof(master); err != nil {
+	if err := c.app.slaveof(masterAddr); err != nil {
 		return err
 	}
 
diff --git a/server/replication.go b/server/replication.go
index d1a3749..81ba85e 100644
--- a/server/replication.go
+++ b/server/replication.go
@@ -1,9 +1,87 @@
 package server
 
-func (app *App) slaveof(master string) error {
+import (
+	"encoding/json"
+	"github.com/siddontang/go-log/log"
+	"io/ioutil"
+	"os"
+	"path"
+)
+
+type masterInfo struct {
+	Addr    string `json:"addr"`
+	LogFile string `json:"log_name"`
+	LogPos  int64  `json:"log_pos"`
+}
+
+func (app *App) getMasterInfoName() string {
+	return path.Join(app.cfg.DataDir, "master.info")
+}
+
+func (app *App) loadMasterInfo() error {
+	data, err := ioutil.ReadFile(app.getMasterInfoName())
+	if err != nil {
+		if os.IsNotExist(err) {
+			return nil
+		} else {
+			return err
+		}
+	}
+
+	if err = json.Unmarshal(data, &app.master); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (app *App) saveMasterInfo() error {
+	bakName := path.Join(app.cfg.DataDir, "master.info.bak")
+
+	data, err := json.Marshal(&app.master)
+	if err != nil {
+		return err
+	}
+
+	var fd *os.File
+	fd, err = os.OpenFile(bakName, os.O_CREATE|os.O_WRONLY, os.ModePerm)
+	if err != nil {
+		return err
+	}
+
+	if _, err = fd.Write(data); err != nil {
+		fd.Close()
+		return err
+	}
+
+	fd.Close()
+	return os.Rename(bakName, app.getMasterInfoName())
+}
+
+func (app *App) slaveof(masterAddr string) error {
+	if len(masterAddr) == 0 {
+		//stop replication
+	} else {
+	}
+
 	return nil
 }
 
 func (app *App) runReplication() {
-
+}
+
+func (app *App) startReplication(masterAddr string) error {
+	if err := app.loadMasterInfo(); err != nil {
+		log.Error("load master.info error %s, use fullsync", err.Error())
+		app.master = masterInfo{masterAddr, "", 0}
+	} else if app.master.Addr != masterAddr {
+		if err := app.ldb.FlushAll(); err != nil {
+			log.Error("replication flush old data error %s", err.Error())
+			return err
+		}
+
+		app.master = masterInfo{masterAddr, "", 0}
+	}
+
+	return nil
 }