diff --git a/common/buf/buffer.go b/common/buf/buffer.go
index 75d93b5af..e0509a174 100644
--- a/common/buf/buffer.go
+++ b/common/buf/buffer.go
@@ -139,11 +139,6 @@ func (b *Buffer) Write(data []byte) (int, error) {
 	return nBytes, nil
 }
 
-// WriteBytes appends one or more bytes to the end of the buffer.
-func (b *Buffer) WriteBytes(bytes ...byte) (int, error) {
-	return b.Write(bytes)
-}
-
 // WriteByte writes a single byte into the buffer.
 func (b *Buffer) WriteByte(v byte) error {
 	if b.IsFull() {
diff --git a/common/buf/buffer_test.go b/common/buf/buffer_test.go
index d45677ab0..c61ff7d88 100644
--- a/common/buf/buffer_test.go
+++ b/common/buf/buffer_test.go
@@ -96,3 +96,63 @@ func BenchmarkNewBuffer(b *testing.B) {
 		buffer.Release()
 	}
 }
+
+func BenchmarkWrite2(b *testing.B) {
+	buffer := New()
+
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		_, _ = buffer.Write([]byte{'a', 'b'})
+		buffer.Clear()
+	}
+}
+
+func BenchmarkWrite8(b *testing.B) {
+	buffer := New()
+
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		_, _ = buffer.Write([]byte{'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h'})
+		buffer.Clear()
+	}
+}
+
+func BenchmarkWrite32(b *testing.B) {
+	buffer := New()
+	payload := make([]byte, 32)
+	rand.Read(payload)
+
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		_, _ = buffer.Write(payload)
+		buffer.Clear()
+	}
+}
+
+func BenchmarkWriteByte2(b *testing.B) {
+	buffer := New()
+
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		_ = buffer.WriteByte('a')
+		_ = buffer.WriteByte('b')
+		buffer.Clear()
+	}
+}
+
+func BenchmarkWriteByte8(b *testing.B) {
+	buffer := New()
+
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		_ = buffer.WriteByte('a')
+		_ = buffer.WriteByte('b')
+		_ = buffer.WriteByte('c')
+		_ = buffer.WriteByte('d')
+		_ = buffer.WriteByte('e')
+		_ = buffer.WriteByte('f')
+		_ = buffer.WriteByte('g')
+		_ = buffer.WriteByte('h')
+		buffer.Clear()
+	}
+}
diff --git a/common/buf/multi_buffer_test.go b/common/buf/multi_buffer_test.go
index 84592792f..0ec46ef1a 100644
--- a/common/buf/multi_buffer_test.go
+++ b/common/buf/multi_buffer_test.go
@@ -14,10 +14,10 @@ func TestMultiBufferRead(t *testing.T) {
 	assert := With(t)
 
 	b1 := New()
-	b1.WriteBytes('a', 'b')
+	b1.WriteString("ab")
 
 	b2 := New()
-	b2.WriteBytes('c', 'd')
+	b2.WriteString("cd")
 	mb := NewMultiBufferValue(b1, b2)
 
 	bs := make([]byte, 32)
@@ -32,7 +32,7 @@ func TestMultiBufferAppend(t *testing.T) {
 
 	var mb MultiBuffer
 	b := New()
-	b.WriteBytes('a', 'b')
+	b.WriteString("ab")
 	mb.Append(b)
 	assert(mb.Len(), Equals, int32(2))
 }
diff --git a/common/buf/reader_test.go b/common/buf/reader_test.go
index 9e3458423..272ab5a9a 100644
--- a/common/buf/reader_test.go
+++ b/common/buf/reader_test.go
@@ -17,9 +17,9 @@ func TestBytesReaderWriteTo(t *testing.T) {
 	pReader, pWriter := pipe.New(pipe.WithSizeLimit(1024))
 	reader := &BufferedReader{Reader: pReader}
 	b1 := New()
-	b1.WriteBytes('a', 'b', 'c')
+	b1.WriteString("abc")
 	b2 := New()
-	b2.WriteBytes('e', 'f', 'g')
+	b2.WriteString("efg")
 	assert(pWriter.WriteMultiBuffer(NewMultiBufferValue(b1, b2)), IsNil)
 	pWriter.Close()
 
@@ -44,9 +44,9 @@ func TestBytesReaderMultiBuffer(t *testing.T) {
 	pReader, pWriter := pipe.New(pipe.WithSizeLimit(1024))
 	reader := &BufferedReader{Reader: pReader}
 	b1 := New()
-	b1.WriteBytes('a', 'b', 'c')
+	b1.WriteString("abc")
 	b2 := New()
-	b2.WriteBytes('e', 'f', 'g')
+	b2.WriteString("efg")
 	assert(pWriter.WriteMultiBuffer(NewMultiBufferValue(b1, b2)), IsNil)
 	pWriter.Close()
 
diff --git a/common/crypto/chunk_test.go b/common/crypto/chunk_test.go
index 47402de18..90409fc3b 100644
--- a/common/crypto/chunk_test.go
+++ b/common/crypto/chunk_test.go
@@ -20,11 +20,11 @@ func TestChunkStreamIO(t *testing.T) {
 	reader := NewChunkStreamReader(PlainChunkSizeParser{}, cache)
 
 	b := buf.New()
-	b.WriteBytes('a', 'b', 'c', 'd')
+	b.WriteString("abcd")
 	common.Must(writer.WriteMultiBuffer(buf.NewMultiBufferValue(b)))
 
 	b = buf.New()
-	b.WriteBytes('e', 'f', 'g')
+	b.WriteString("efg")
 	common.Must(writer.WriteMultiBuffer(buf.NewMultiBufferValue(b)))
 
 	common.Must(writer.WriteMultiBuffer(buf.MultiBuffer{}))
diff --git a/proxy/blackhole/config.go b/proxy/blackhole/config.go
index 2a0da01d0..6cd629a20 100644
--- a/proxy/blackhole/config.go
+++ b/proxy/blackhole/config.go
@@ -27,7 +27,7 @@ func (*NoneResponse) WriteTo(buf.Writer) int32 { return 0 }
 // WriteTo implements ResponseConfig.WriteTo().
 func (*HTTPResponse) WriteTo(writer buf.Writer) int32 {
 	b := buf.New()
-	common.Must2(b.Write([]byte(http403response)))
+	common.Must2(b.WriteString(http403response))
 	n := b.Len()
 	writer.WriteMultiBuffer(buf.NewMultiBufferValue(b))
 	return n
diff --git a/proxy/shadowsocks/ota_test.go b/proxy/shadowsocks/ota_test.go
index 3bd11b865..de7c1d9a4 100644
--- a/proxy/shadowsocks/ota_test.go
+++ b/proxy/shadowsocks/ota_test.go
@@ -12,8 +12,7 @@ func TestNormalChunkReading(t *testing.T) {
 	assert := With(t)
 
 	buffer := buf.New()
-	buffer.WriteBytes(
-		0, 8, 39, 228, 69, 96, 133, 39, 254, 26, 201, 70, 11, 12, 13, 14, 15, 16, 17, 18)
+	buffer.Write([]byte{0, 8, 39, 228, 69, 96, 133, 39, 254, 26, 201, 70, 11, 12, 13, 14, 15, 16, 17, 18})
 	reader := NewChunkReader(buffer, NewAuthenticator(ChunkKeyGenerator(
 		[]byte{21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36})))
 	payload, err := reader.ReadMultiBuffer()
diff --git a/proxy/socks/protocol.go b/proxy/socks/protocol.go
index 319b3adaf..cdc98c7c5 100644
--- a/proxy/socks/protocol.go
+++ b/proxy/socks/protocol.go
@@ -255,7 +255,7 @@ func writeSocks5Response(writer io.Writer, errCode byte, address net.Address, po
 	buffer := buf.New()
 	defer buffer.Release()
 
-	common.Must2(buffer.WriteBytes(socks5Version, errCode, 0x00 /* reserved */))
+	common.Must2(buffer.Write([]byte{socks5Version, errCode, 0x00 /* reserved */}))
 	if err := addrParser.WriteAddressPort(buffer, address, port); err != nil {
 		return err
 	}
@@ -267,7 +267,8 @@ func writeSocks4Response(writer io.Writer, errCode byte, address net.Address, po
 	buffer := buf.New()
 	defer buffer.Release()
 
-	common.Must2(buffer.WriteBytes(0x00, errCode))
+	common.Must(buffer.WriteByte(0x00))
+	common.Must(buffer.WriteByte(errCode))
 	common.Must2(serial.WriteUint16(buffer, port.Value()))
 	common.Must2(buffer.Write(address.IP()))
 	return buf.WriteAllBytes(writer, buffer.Bytes())
@@ -300,7 +301,7 @@ func DecodeUDPPacket(packet *buf.Buffer) (*protocol.RequestHeader, error) {
 
 func EncodeUDPPacket(request *protocol.RequestHeader, data []byte) (*buf.Buffer, error) {
 	b := buf.New()
-	common.Must2(b.WriteBytes(0, 0, 0 /* Fragment */))
+	common.Must2(b.Write([]byte{0, 0, 0 /* Fragment */}))
 	if err := addrParser.WriteAddressPort(b, request.Address, request.Port); err != nil {
 		b.Release()
 		return nil, err
@@ -362,14 +363,15 @@ func ClientHandshake(request *protocol.RequestHeader, reader io.Reader, writer i
 	b := buf.New()
 	defer b.Release()
 
-	common.Must2(b.WriteBytes(socks5Version, 0x01, authByte))
+	common.Must2(b.Write([]byte{socks5Version, 0x01, authByte}))
 	if authByte == authPassword {
 		account := request.User.Account.(*Account)
 
-		common.Must2(b.WriteBytes(0x01, byte(len(account.Username))))
-		common.Must2(b.Write([]byte(account.Username)))
-		common.Must2(b.WriteBytes(byte(len(account.Password))))
-		common.Must2(b.Write([]byte(account.Password)))
+		common.Must(b.WriteByte(0x01))
+		common.Must(b.WriteByte(byte(len(account.Username))))
+		common.Must2(b.WriteString(account.Username))
+		common.Must(b.WriteByte(byte(len(account.Password))))
+		common.Must2(b.WriteString(account.Password))
 	}
 
 	if err := buf.WriteAllBytes(writer, b.Bytes()); err != nil {
@@ -404,7 +406,7 @@ func ClientHandshake(request *protocol.RequestHeader, reader io.Reader, writer i
 	if request.Command == protocol.RequestCommandUDP {
 		command = byte(cmdUDPPort)
 	}
-	common.Must2(b.WriteBytes(socks5Version, command, 0x00 /* reserved */))
+	common.Must2(b.Write([]byte{socks5Version, command, 0x00 /* reserved */}))
 	if err := addrParser.WriteAddressPort(b, request.Address, request.Port); err != nil {
 		return nil, err
 	}
diff --git a/proxy/vmess/encoding/client.go b/proxy/vmess/encoding/client.go
index c35f5e210..a75631a9e 100644
--- a/proxy/vmess/encoding/client.go
+++ b/proxy/vmess/encoding/client.go
@@ -65,14 +65,15 @@ func (c *ClientSession) EncodeRequestHeader(header *protocol.RequestHeader, writ
 	buffer := buf.New()
 	defer buffer.Release()
 
-	common.Must2(buffer.WriteBytes(Version))
+	common.Must(buffer.WriteByte(Version))
 	common.Must2(buffer.Write(c.requestBodyIV[:]))
 	common.Must2(buffer.Write(c.requestBodyKey[:]))
-	common.Must2(buffer.WriteBytes(c.responseHeader, byte(header.Option)))
+	common.Must(buffer.WriteByte(c.responseHeader))
+	common.Must(buffer.WriteByte(byte(header.Option)))
 
 	padingLen := dice.Roll(16)
 	security := byte(padingLen<<4) | byte(header.Security)
-	common.Must2(buffer.WriteBytes(security, byte(0), byte(header.Command)))
+	common.Must2(buffer.Write([]byte{security, byte(0), byte(header.Command)}))
 
 	if header.Command != protocol.RequestCommandMux {
 		if err := addrParser.WriteAddressPort(buffer, header.Address, header.Port); err != nil {
diff --git a/transport/internet/kcp/segment_test.go b/transport/internet/kcp/segment_test.go
index b60d26ebb..f4369e15e 100644
--- a/transport/internet/kcp/segment_test.go
+++ b/transport/internet/kcp/segment_test.go
@@ -50,7 +50,7 @@ func Test1ByteDataSegment(t *testing.T) {
 		Number:      4,
 		SendingNext: 5,
 	}
-	seg.Data().WriteBytes('a')
+	seg.Data().WriteByte('a')
 
 	nBytes := seg.ByteSize()
 	bytes := make([]byte, nBytes)
diff --git a/transport/internet/udp/dispatcher_test.go b/transport/internet/udp/dispatcher_test.go
index 0dd93ff7e..329b7b562 100644
--- a/transport/internet/udp/dispatcher_test.go
+++ b/transport/internet/udp/dispatcher_test.go
@@ -63,7 +63,7 @@ func TestSameDestinationDispatching(t *testing.T) {
 	dest := net.UDPDestination(net.LocalHostIP, 53)
 
 	b := buf.New()
-	b.WriteBytes('a', 'b', 'c', 'd')
+	b.WriteString("abcd")
 
 	var msgCount uint32
 	dispatcher := NewDispatcher(td, func(ctx context.Context, payload *buf.Buffer) {
diff --git a/transport/pipe/pipe_test.go b/transport/pipe/pipe_test.go
index 964043342..6ab787558 100644
--- a/transport/pipe/pipe_test.go
+++ b/transport/pipe/pipe_test.go
@@ -103,7 +103,7 @@ func TestPipeWriteMultiThread(t *testing.T) {
 		wg.Add(1)
 		go func() {
 			b := buf.New()
-			b.WriteBytes('a', 'b', 'c', 'd')
+			b.WriteString("abcd")
 			pWriter.WriteMultiBuffer(buf.NewMultiBufferValue(b))
 			wg.Done()
 		}()