diff --git a/dtmcli/dtmimp/consts.go b/dtmcli/dtmimp/consts.go
index 050d086..4248d62 100644
--- a/dtmcli/dtmimp/consts.go
+++ b/dtmcli/dtmimp/consts.go
@@ -19,4 +19,6 @@ const (
 	DBTypePostgres = "postgres"
 	// DBTypeRedis const for driver redis
 	DBTypeRedis = "redis"
+	// Jrpc const for json-rpc
+	Jrpc = "json-rpc"
 )
diff --git a/dtmcli/dtmimp/trans_base.go b/dtmcli/dtmimp/trans_base.go
index 4ec247b..3024ead 100644
--- a/dtmcli/dtmimp/trans_base.go
+++ b/dtmcli/dtmimp/trans_base.go
@@ -94,7 +94,7 @@ func TransCallDtm(tb *TransBase, body interface{}, operation string) error {
 	if tb.RequestTimeout != 0 {
 		RestyClient.SetTimeout(time.Duration(tb.RequestTimeout) * time.Second)
 	}
-	if tb.Protocol == "json-rpc" {
+	if tb.Protocol == Jrpc {
 		var result map[string]interface{}
 		resp, err := RestyClient.R().
 			SetBody(map[string]interface{}{
diff --git a/test/msg_jrpc_test.go b/test/msg_jrpc_test.go
index 88438fc..61534ae 100644
--- a/test/msg_jrpc_test.go
+++ b/test/msg_jrpc_test.go
@@ -33,7 +33,7 @@ func TestMsgJrpcDoAndSubmit(t *testing.T) {
 	req := busi.GenTransReq(30, false, false)
 	msg := dtmcli.NewMsg(dtmutil.DefaultJrpcServer, gid).
 		Add(busi.Busi+"/SagaBTransIn", req)
-	msg.Protocol = "json-rpc"
+	msg.Protocol = dtmimp.Jrpc
 	err := msg.DoAndSubmitDB(Busi+"/QueryPreparedB", dbGet().ToSQLDB(), func(tx *sql.Tx) error {
 		return busi.SagaAdjustBalance(tx, busi.TransOutUID, -req.Amount, "SUCCESS")
 	})
@@ -50,7 +50,7 @@ func TestMsgJrpcDoAndSubmitBusiFailed(t *testing.T) {
 	req := busi.GenTransReq(30, false, false)
 	msg := dtmcli.NewMsg(dtmutil.DefaultJrpcServer, gid).
 		Add(busi.Busi+"/SagaBTransIn", req)
-	msg.Protocol = "json-rpc"
+	msg.Protocol = dtmimp.Jrpc
 	err := msg.DoAndSubmitDB(Busi+"/QueryPreparedB", dbGet().ToSQLDB(), func(tx *sql.Tx) error {
 		return errors.New("an error")
 	})
@@ -75,7 +75,7 @@ func TestMsgJprcAbnormal(t *testing.T) {
 	assert.Nil(t, err)
 	assert.Contains(t, resp.String(), "-32700")
 
-	resp, err = dtmcli.GetRestyClient().R().SetBody("hello").Post("http://localhost:1001")
+	_, err = dtmcli.GetRestyClient().R().SetBody("hello").Post("http://localhost:1001")
 	assert.Error(t, err)
 
 	resp, err = dtmcli.GetRestyClient().R().SetBody(map[string]string{
@@ -121,6 +121,6 @@ func genJrpcMsg(gid string) *dtmcli.Msg {
 		Add(busi.Busi+"/TransOut", &req).
 		Add(busi.Busi+"/TransIn", &req)
 	msg.QueryPrepared = busi.Busi + "/QueryPrepared"
-	msg.Protocol = "json-rpc"
+	msg.Protocol = dtmimp.Jrpc
 	return msg
 }
diff --git a/test/tcc_jrpc_test.go b/test/tcc_jrpc_test.go
index d219b28..31bdafe 100644
--- a/test/tcc_jrpc_test.go
+++ b/test/tcc_jrpc_test.go
@@ -15,7 +15,7 @@ func TestTccJrpcNormal(t *testing.T) {
 	req := busi.GenTransReq(30, false, false)
 	gid := dtmimp.GetFuncName()
 	err := dtmcli.TccGlobalTransaction2(dtmutil.DefaultJrpcServer, gid, func(tcc *dtmcli.Tcc) {
-		tcc.Protocol = "json-rpc"
+		tcc.Protocol = dtmimp.Jrpc
 	}, func(tcc *dtmcli.Tcc) (*resty.Response, error) {
 		_, err := tcc.CallBranch(req, Busi+"/TransOut", Busi+"/TransOutConfirm", Busi+"/TransOutRevert")
 		assert.Nil(t, err)