diff --git a/clients/naming_client/naming_grpc/naming_grpc_proxy.go b/clients/naming_client/naming_grpc/naming_grpc_proxy.go
index 9f791788..83bfb084 100644
--- a/clients/naming_client/naming_grpc/naming_grpc_proxy.go
+++ b/clients/naming_client/naming_grpc/naming_grpc_proxy.go
@@ -158,8 +158,8 @@ func (proxy *NamingGrpcProxy) ServerHealthy() bool {
 }
 
 // QueryInstancesOfService ...
-func (proxy *NamingGrpcProxy) QueryInstancesOfService(serviceName, groupName, clusters string, udpPort int, healthyOnly bool) (*model.Service, error) {
-	response, err := proxy.requestToServer(rpc_request.NewServiceQueryRequest(proxy.clientConfig.NamespaceId, serviceName, groupName, clusters,
+func (proxy *NamingGrpcProxy) QueryInstancesOfService(serviceName, groupName, cluster string, udpPort int, healthyOnly bool) (*model.Service, error) {
+	response, err := proxy.requestToServer(rpc_request.NewServiceQueryRequest(proxy.clientConfig.NamespaceId, serviceName, groupName, cluster,
 		healthyOnly, udpPort))
 	if err != nil {
 		return nil, err
diff --git a/common/remote/rpc/rpc_request/naming_request.go b/common/remote/rpc/rpc_request/naming_request.go
index b03cd4e7..c54e943f 100644
--- a/common/remote/rpc/rpc_request/naming_request.go
+++ b/common/remote/rpc/rpc_request/naming_request.go
@@ -138,15 +138,15 @@ func (r *SubscribeServiceRequest) GetRequestType() string {
 
 type ServiceQueryRequest struct {
 	*NamingRequest
-	Clusters    string `json:"clusters"`
+	Cluster     string `json:"cluster"`
 	HealthyOnly bool   `json:"healthyOnly"`
 	UdpPort     int    `json:"udpPort"`
 }
 
-func NewServiceQueryRequest(namespace, serviceName, groupName, clusters string, healthyOnly bool, udpPort int) *ServiceQueryRequest {
+func NewServiceQueryRequest(namespace, serviceName, groupName, cluster string, healthyOnly bool, udpPort int) *ServiceQueryRequest {
 	return &ServiceQueryRequest{
 		NamingRequest: NewNamingRequest(namespace, serviceName, groupName),
-		Clusters:      clusters,
+		Cluster:       cluster,
 		HealthyOnly:   healthyOnly,
 		UdpPort:       udpPort,
 	}
diff --git a/example/service/main.go b/example/service/main.go
index a07dac97..8a16c10d 100644
--- a/example/service/main.go
+++ b/example/service/main.go
@@ -129,6 +129,7 @@ func main() {
 		ServiceName: "demo.go",
 		GroupName:   "group-a",
 		Clusters:    []string{"cluster-a"},
+		HealthyOnly: true,
 	})
 
 	//SelectOneHealthyInstance return one instance by WRR strategy for load balance
@@ -154,7 +155,7 @@ func main() {
 	//wait for client pull change from server
 	time.Sleep(3 * time.Second)
 
-	/*updateServiceInstance(client, vo.UpdateInstanceParam{
+	updateServiceInstance(client, vo.UpdateInstanceParam{
 		Ip:          "10.0.0.11", //update ip
 		Port:        8848,
 		ServiceName: "demo.go",
@@ -165,7 +166,7 @@ func main() {
 		Healthy:     true,
 		Ephemeral:   true,
 		Metadata:    map[string]string{"idc": "beijing1"}, //update metadata
-	})*/
+	})
 
 	//wait for client pull change from server
 	time.Sleep(3 * time.Second)
diff --git a/vo/service_param.go b/vo/service_param.go
index f68e13ee..35387ccd 100644
--- a/vo/service_param.go
+++ b/vo/service_param.go
@@ -89,7 +89,7 @@ type SelectInstancesParam struct {
 	Clusters    []string `param:"clusters"`    //optional
 	ServiceName string   `param:"serviceName"` //required
 	GroupName   string   `param:"groupName"`   //optional,default:DEFAULT_GROUP
-	HealthyOnly bool     `param:"healthyOnly"` //optional,return only healthy instance
+	HealthyOnly bool     `param:"healthyOnly"` //optional,value = true return only healthy instance, value = false return only unHealthy instance
 }
 
 type SelectOneHealthInstanceParam struct {