diff --git a/encoding/json/json_test.go b/encoding/json/json_test.go
index 5eab1ba37..b43e4ef70 100644
--- a/encoding/json/json_test.go
+++ b/encoding/json/json_test.go
@@ -1,7 +1,8 @@
 package json
 
 import (
-	"bytes"
+	"encoding/json"
+	"reflect"
 	"strings"
 	"testing"
 
@@ -21,6 +22,47 @@ type testMessage struct {
 	Embed  *testEmbed `json:"embed,omitempty"`
 }
 
+type mock struct {
+	value int
+}
+
+const (
+	Unknown = iota
+	Gopher
+	Zebra
+)
+
+func (a *mock) UnmarshalJSON(b []byte) error {
+	var s string
+	if err := json.Unmarshal(b, &s); err != nil {
+		return err
+	}
+	switch strings.ToLower(s) {
+	default:
+		a.value = Unknown
+	case "gopher":
+		a.value = Gopher
+	case "zebra":
+		a.value = Zebra
+	}
+
+	return nil
+}
+
+func (a *mock) MarshalJSON() ([]byte, error) {
+	var s string
+	switch a.value {
+	default:
+		s = "unknown"
+	case Gopher:
+		s = "gopher"
+	case Zebra:
+		s = "zebra"
+	}
+
+	return json.Marshal(s)
+}
+
 func TestJSON_Marshal(t *testing.T) {
 	tests := []struct {
 		input  interface{}
@@ -38,6 +80,10 @@ func TestJSON_Marshal(t *testing.T) {
 			input:  &testData.TestModel{Id: 1, Name: "go-kratos", Hobby: []string{"1", "2"}},
 			expect: `{"id":"1","name":"go-kratos","hobby":["1","2"],"attrs":{}}`,
 		},
+		{
+			input:  &mock{value: Gopher},
+			expect: `"gopher"`,
+		},
 	}
 	for _, v := range tests {
 		data, err := (codec{}).Marshal(v.input)
@@ -55,8 +101,10 @@ func TestJSON_Marshal(t *testing.T) {
 }
 
 func TestJSON_Unmarshal(t *testing.T) {
-	p := &testMessage{}
-	p2 := &testData.TestModel{}
+	p := testMessage{}
+	p2 := testData.TestModel{}
+	p3 := &testData.TestModel{}
+	p4 := &mock{}
 	tests := []struct {
 		input  string
 		expect interface{}
@@ -70,13 +118,21 @@ func TestJSON_Unmarshal(t *testing.T) {
 			expect: &p,
 		},
 		{
-			input:  `{"id":1,"name":"kratos"}`,
+			input:  `{"id":"1","name":"go-kratos","hobby":["1","2"],"attrs":{}}`,
 			expect: &p2,
 		},
+		{
+			input:  `{"id":1,"name":"go-kratos","hobby":["1","2"]}`,
+			expect: &p3,
+		},
+		{
+			input:  `"zebra"`,
+			expect: p4,
+		},
 	}
 	for _, v := range tests {
 		want := []byte(v.input)
-		err := (codec{}).Unmarshal(want, &v.expect)
+		err := (codec{}).Unmarshal(want, v.expect)
 		if err != nil {
 			t.Errorf("marshal(%#v): %s", v.input, err)
 		}
@@ -84,7 +140,7 @@ func TestJSON_Unmarshal(t *testing.T) {
 		if err != nil {
 			t.Errorf("marshal(%#v): %s", v.input, err)
 		}
-		if !bytes.Equal(got, want) {
+		if !reflect.DeepEqual(strings.ReplaceAll(string(got), " ", ""), strings.ReplaceAll(string(want), " ", "")) {
 			t.Errorf("marshal(%#v):\nhave %#q\nwant %#q", v.input, got, want)
 		}
 	}