diff --git a/internal/protcl/resp3.go b/internal/protcl/resp3.go
index 8d1d94f..8c2fed4 100644
--- a/internal/protcl/resp3.go
+++ b/internal/protcl/resp3.go
@@ -39,11 +39,55 @@ type Resp3 struct {
 	Elems   []*Resp3
 }
 
-func (r *Resp3) String() string {
-	return r.string("")
+// RenderString convert resp3 to show-message on client
+func (r *Resp3) RenderString() string {
+	return r.renderString("")
 }
 
-func (r *Resp3) string(pre string) string {
+// ProtocolString convert resp3 to protocol raw string
+func (r *Resp3) ProtocolString() string {
+	buf := new(strings.Builder)
+	buf.WriteByte(r.Type)
+	r.protocolString(buf)
+	return buf.String()
+}
+
+func (r *Resp3) protocolString(buf *strings.Builder) {
+	switch r.Type {
+	case RepSimpleString, Resp3SimpleError:
+		buf.WriteString(r.Str)
+	case Resp3BlobString, Resp3BolbError:
+		buf.WriteString(strconv.Itoa(len(r.Str)))
+		buf.WriteByte('\n')
+		buf.WriteString(r.Str)
+	case Resp3Number:
+		buf.WriteString(strconv.Itoa(r.Integer))
+	case Resp3Double:
+		buf.WriteString(strconv.FormatFloat(r.Double, 'f', -1, 64))
+	case Resp3BigNumber:
+		buf.WriteString(r.BigInt.String())
+	case Resp3Null:
+	case Resp3Boolean:
+		if r.Boolean {
+			buf.WriteByte('t')
+		} else {
+			buf.WriteByte('f')
+		}
+	case Resp3Array, Resp3Set:
+		buf.WriteString(strconv.Itoa(len(r.Elems)))
+		buf.WriteByte('\n')
+
+		for _, v := range r.Elems {
+			buf.WriteByte(v.Type)
+			v.protocolString(buf)
+		}
+		return
+	}
+
+	buf.WriteByte('\n')
+}
+
+func (r *Resp3) renderString(pre string) string {
 	switch r.Type {
 	case RepSimpleString, Resp3BlobString:
 		return fmt.Sprintf("%s%q", pre, r.Str)
@@ -72,7 +116,7 @@ func (r *Resp3) string(pre string) string {
 		}
 		for _, elem := range r.Elems {
 			str.WriteString("\n")
-			str.WriteString(elem.string(pre + "\t"))
+			str.WriteString(elem.renderString(pre + "\t"))
 		}
 		return str.String()
 	}
diff --git a/internal/protcl/resp3_test.go b/internal/protcl/resp3_test.go
index 9a76ec3..ccb5f8e 100644
--- a/internal/protcl/resp3_test.go
+++ b/internal/protcl/resp3_test.go
@@ -2,6 +2,7 @@ package protcl
 
 import (
 	"bufio"
+	"math/big"
 	"strings"
 	"testing"
 
@@ -14,7 +15,7 @@ func testResp3Parser(t *testing.T, input, expect string) {
 	parser := NewResp3Parser(bufio.NewReader(strings.NewReader(input)))
 	result, err := parser.Parse()
 	assert.Nil(err)
-	assert.Equal(expect, result.String())
+	assert.Equal(expect, result.RenderString())
 }
 
 func testResp3Error(t *testing.T, input, e string) {
@@ -27,59 +28,138 @@ func testResp3Error(t *testing.T, input, e string) {
 	assert.Equal(e, err.Error())
 }
 
+type TestResp3 struct {
+	resp3    *Resp3
+	protocol string
+	render   string
+	err      string
+}
+
 func TestResp3Parser(t *testing.T) {
-	// simple string
-	testResp3Error(t, "+string", `EOF`)
-	testResp3Parser(t, "+string\n", `"string"`)
-
-	// blob string
-	testResp3Parser(t, "$0\n\n", `""`)
-	testResp3Error(t, "$1\n\n", `unexpected line end`)
-	testResp3Error(t, "$1\naa\n", `unexpected line end`)
-	testResp3Parser(t, "$10\n1234567890\n", `"1234567890"`)
-
-	// simple error
-	testResp3Parser(t, "-error\n", `(error) error`)
-	testResp3Parser(t, "-Err error\n", `(error) Err error`)
-
-	// blob error
-	testResp3Parser(t, "!3\nerr\n", `(error) err`)
-	testResp3Parser(t, "!17\nErr this is error\n", `(error) Err this is error`)
-
-	// number
-	testResp3Parser(t, ":-1\n", `(integer) -1`)
-	testResp3Parser(t, ":0\n", `(integer) 0`)
-	testResp3Parser(t, ":100\n", `(integer) 100`)
-
-	// double
-	testResp3Parser(t, ",-1\n", `(double) -1`)
-	testResp3Parser(t, ",0\n", `(double) 0`)
-	testResp3Parser(t, ",10\n", `(double) 10`)
-	testResp3Parser(t, ",.1\n", `(double) 0.1`)
-	testResp3Parser(t, ",1.23\n", `(double) 1.23`)
-	testResp3Parser(t, ",1.\n", `(double) 1`)
-	testResp3Error(t, ",invalid\n", `convert invalid to double fail, because of strconv.ParseFloat: parsing "invalid": invalid syntax`)
-
-	// big number
-	testResp3Parser(t, "(3492890328409238509324850943850943825024385\n", `(big number) 3492890328409238509324850943850943825024385`)
-	testResp3Error(t, "(invalid string\n", `convert invalid string to Big Number fail`)
-
-	// null
-	testResp3Parser(t, "_\n", "(null)")
-
-	// boolean
-	testResp3Parser(t, "#t\n", `(boolean) true`)
-	testResp3Parser(t, "#f\n", `(boolean) false`)
-	testResp3Error(t, "#x\n", `unexpect string: t/f`)
-	testResp3Error(t, "#\n", `unexpected line end`)
-
-	// array
-	testResp3Error(t, "*3\n:1\n:2\n", "EOF")
-	testResp3Parser(t, "*3\n:1\n:2\n:3\n", "(array)\n\t(integer) 1\n\t(integer) 2\n\t(integer) 3")
-	testResp3Parser(t, "*2\n*3\n:1\n$5\nhello\n:2\n#f\n", "(array)\n\t(array)\n\t\t(integer) 1\n\t\t\"hello\"\n\t\t(integer) 2\n\t(boolean) false")
-
-	// set
-	testResp3Error(t, "~3\n:1\n:2\n", "EOF")
-	testResp3Parser(t, "~3\n:1\n:2\n:3\n", "(set)\n\t(integer) 1\n\t(integer) 2\n\t(integer) 3")
-	testResp3Parser(t, "~2\n*3\n:1\n$5\nhello\n:2\n#f\n", "(set)\n\t(array)\n\t\t(integer) 1\n\t\t\"hello\"\n\t\t(integer) 2\n\t(boolean) false")
+	assert := testifyAssert.New(t)
+
+	bigNumber, _ := big.NewInt(0).SetString("3492890328409238509324850943850943825024385", 10)
+	testCases := []TestResp3{
+		// simple renderString
+		{protocol: "+renderString", err: "EOF"},
+		{resp3: &Resp3{Type: Resp3SimpleString, Str: ""}, protocol: "+\n", render: `""`},
+		{resp3: &Resp3{Type: Resp3SimpleString, Str: "hello"}, protocol: "+hello\n", render: `"hello"`},
+		{resp3: &Resp3{Type: Resp3SimpleString, Str: "hello world"}, protocol: "+hello world\n", render: `"hello world"`},
+
+		// blob renderString
+		{protocol: "$1\n\n", err: "unexpected line end"},
+		{protocol: "$1\naa\n", err: "unexpected line end"},
+		{resp3: &Resp3{Type: Resp3BlobString, Str: ""}, protocol: "$0\n\n", render: `""`},
+		{resp3: &Resp3{Type: Resp3BlobString, Str: "hello"}, protocol: "$5\nhello\n", render: `"hello"`},
+		{resp3: &Resp3{Type: Resp3BlobString, Str: "hello\nworld"}, protocol: "$11\nhello\nworld\n", render: "\"hello\\nworld\""},
+
+		// simple error
+		{protocol: "-renderString", err: "EOF"},
+		{resp3: &Resp3{Type: Resp3SimpleError, Str: ""}, protocol: "-\n", render: `(error) `},
+		{resp3: &Resp3{Type: Resp3SimpleError, Str: "hello"}, protocol: "-hello\n", render: `(error) hello`},
+		{resp3: &Resp3{Type: Resp3SimpleError, Str: "hello world"}, protocol: "-hello world\n", render: `(error) hello world`},
+
+		// blob error
+		{protocol: "!1\n\n", err: "unexpected line end"},
+		{protocol: "!1\naa\n", err: "unexpected line end"},
+		{resp3: &Resp3{Type: Resp3BolbError, Str: ""}, protocol: "!0\n\n", render: `(error) `},
+		{resp3: &Resp3{Type: Resp3BolbError, Str: "hello"}, protocol: "!5\nhello\n", render: `(error) hello`},
+		{resp3: &Resp3{Type: Resp3BolbError, Str: "hello\nworld"}, protocol: "!11\nhello\nworld\n", render: "(error) hello\nworld"},
+
+		// number
+		{protocol: ":invalid", err: "EOF"},
+		{protocol: ":invalid\n", err: "ERR: error casting invalid to int"},
+		{resp3: &Resp3{Type: Resp3Number, Integer: -1}, protocol: ":-1\n", render: `(integer) -1`},
+		{resp3: &Resp3{Type: Resp3Number, Integer: 0}, protocol: ":0\n", render: `(integer) 0`},
+		{resp3: &Resp3{Type: Resp3Number, Integer: 100}, protocol: ":100\n", render: `(integer) 100`},
+
+		// double
+		{protocol: ",invalid", err: "EOF"},
+		{protocol: ",invalid\n", err: "convert invalid to double fail, because of strconv.ParseFloat: parsing \"invalid\": invalid syntax"},
+		{resp3: &Resp3{Type: Resp3Double, Double: -1}, protocol: ",-1\n", render: "(double) -1"},
+		{resp3: &Resp3{Type: Resp3Double, Double: 0}, protocol: ",0\n", render: "(double) 0"},
+		{resp3: &Resp3{Type: Resp3Double, Double: 10}, protocol: ",10\n", render: "(double) 10"},
+		{resp3: &Resp3{Type: Resp3Double, Double: 1.23}, protocol: ",1.23\n", render: "(double) 1.23"},
+		{protocol: ",.1\n", render: "(double) 0.1"},
+		{protocol: ",1.\n", render: "(double) 1"},
+
+		// big number
+		{protocol: "(invalid", err: "EOF"},
+		{protocol: "(invalid\n", err: "convert invalid to Big Number fail"},
+		{resp3: &Resp3{Type: Resp3BigNumber, BigInt: bigNumber}, protocol: "(3492890328409238509324850943850943825024385\n", render: "(big number) 3492890328409238509324850943850943825024385"},
+
+		// null
+		{protocol: "_invalid", err: "unexpect string: <LF>"},
+		{protocol: "_invalid\n", err: "unexpect string: <LF>"},
+		{resp3: &Resp3{Type: Resp3Null}, protocol: "_\n", render: "(null)"},
+
+		// boolean
+		{protocol: "#", err: "EOF"},
+		{protocol: "#\n", err: "unexpected line end"},
+		{protocol: "#x\n", err: "unexpect string: t/f"},
+		{protocol: "#invalid", err: "unexpected line end"},
+		{protocol: "#invalid\n", err: "unexpected line end"},
+		{resp3: &Resp3{Type: Resp3Boolean, Boolean: true}, protocol: "#t\n", render: "(boolean) true"},
+		{resp3: &Resp3{Type: Resp3Boolean, Boolean: false}, protocol: "#f\n", render: "(boolean) false"},
+
+		// array
+		{protocol: "*", err: "EOF"},
+		{protocol: "*\n", err: "ERR: error casting  to int"},
+		{protocol: "*invalid", err: "EOF"},
+		{protocol: "*invalid\n", err: "ERR: error casting invalid to int"},
+		{protocol: "*1\n\n", err: "unknown protocol type: \n"},
+		{protocol: "*1\ninvalid\n", err: "unknown protocol type: i"},
+		{protocol: "*3\n:1\n:2\n", err: "EOF"},
+		{resp3: &Resp3{Type: Resp3Array, Elems: []*Resp3{
+			{Type: Resp3Number, Integer: 1},
+			{Type: Resp3Number, Integer: 2},
+			{Type: Resp3Number, Integer: 3},
+		}}, protocol: "*3\n:1\n:2\n:3\n", render: "(array)\n\t(integer) 1\n\t(integer) 2\n\t(integer) 3"},
+		{resp3: &Resp3{Type: Resp3Array, Elems: []*Resp3{
+			{Type: Resp3Array, Elems: []*Resp3{
+				{Type: Resp3Number, Integer: 1},
+				{Type: Resp3BlobString, Str: "hello"},
+				{Type: Resp3Number, Integer: 2},
+			}},
+			{Type: Resp3Boolean, Boolean: false},
+		}}, protocol: "*2\n*3\n:1\n$5\nhello\n:2\n#f\n", render: "(array)\n\t(array)\n\t\t(integer) 1\n\t\t\"hello\"\n\t\t(integer) 2\n\t(boolean) false"},
+
+		// set
+		{protocol: "~", err: "EOF"},
+		{protocol: "~\n", err: "ERR: error casting  to int"},
+		{protocol: "~invalid", err: "EOF"},
+		{protocol: "~invalid\n", err: "ERR: error casting invalid to int"},
+		{protocol: "~1\n\n", err: "unknown protocol type: \n"},
+		{protocol: "~1\ninvalid\n", err: "unknown protocol type: i"},
+		{protocol: "~3\n:1\n:2\n", err: "EOF"},
+		{resp3: &Resp3{Type: Resp3Set, Elems: []*Resp3{
+			{Type: Resp3Number, Integer: 1},
+			{Type: Resp3Number, Integer: 2},
+			{Type: Resp3Number, Integer: 3},
+		}}, protocol: "~3\n:1\n:2\n:3\n", render: "(set)\n\t(integer) 1\n\t(integer) 2\n\t(integer) 3"},
+		{resp3: &Resp3{Type: Resp3Set, Elems: []*Resp3{
+			{Type: Resp3Array, Elems: []*Resp3{
+				{Type: Resp3Number, Integer: 1},
+				{Type: Resp3BlobString, Str: "hello"},
+				{Type: Resp3Number, Integer: 2},
+			}},
+			{Type: Resp3Boolean, Boolean: false},
+		}}, protocol: "~2\n*3\n:1\n$5\nhello\n:2\n#f\n", render: "(set)\n\t(array)\n\t\t(integer) 1\n\t\t\"hello\"\n\t\t(integer) 2\n\t(boolean) false"},
+	}
+
+	for _, testCase := range testCases {
+		if testCase.resp3 == nil {
+			if testCase.render != "" {
+				// protocol renderString -> render renderString
+				testResp3Parser(t, testCase.protocol, testCase.render)
+			} else {
+				// err test
+				testResp3Error(t, testCase.protocol, testCase.err)
+			}
+		} else {
+			// resp3 -> protocol renderString -> render renderString
+			assert.Equal(testCase.protocol, testCase.resp3.ProtocolString())
+			testResp3Parser(t, testCase.protocol, testCase.render)
+		}
+	}
 }