diff --git a/protocol/grpc/client.go b/protocol/grpc/client.go
index 0a98749aa999bbee99d092a47059e9b50a2c890c..af5ac3ff70f08c4c6f03020c8419a1df6aaf0524 100644
--- a/protocol/grpc/client.go
+++ b/protocol/grpc/client.go
@@ -77,7 +77,7 @@ func init() {
 	}
 }
 
-// Client ...
+// Client return grpc connection and warp service stub
 type Client struct {
 	*grpc.ClientConn
 	invoker reflect.Value
diff --git a/protocol/grpc/codec.go b/protocol/grpc/codec.go
index 1f34674d641d1f02f455eda7800cbd56167b89f1..7235a3941baefcdce5964ae21dbdbfe9d6ca9cc8 100644
--- a/protocol/grpc/codec.go
+++ b/protocol/grpc/codec.go
@@ -29,10 +29,8 @@ import (
 )
 
 const (
-	// json
-	CODEC_JSON = "json"
-	// proto
-	CODEC_PROTO = "proto"
+	codecJson  = "json"
+	codecProto = "proto"
 )
 
 func init() {
@@ -44,18 +42,18 @@ func init() {
 	})
 }
 
-// grpcJson ...
 type grpcJson struct {
 	jsonpb.Marshaler
 	jsonpb.Unmarshaler
 }
 
-// implements grpc encoding package Codec interface method
+// Name implements grpc encoding package Codec interface method,
+// returns the name of the Codec implementation.
 func (_ grpcJson) Name() string {
-	return CODEC_JSON
+	return codecJson
 }
 
-// implements grpc encoding package Codec interface method
+// Marshal implements grpc encoding package Codec interface method,returns the wire format of v.
 func (j grpcJson) Marshal(v interface{}) (out []byte, err error) {
 	if pm, ok := v.(proto.Message); ok {
 		b := new(bytes.Buffer)
@@ -68,7 +66,7 @@ func (j grpcJson) Marshal(v interface{}) (out []byte, err error) {
 	return json.Marshal(v)
 }
 
-// implements grpc encoding package Codec interface method
+// Unmarshal implements grpc encoding package Codec interface method,Unmarshal parses the wire format into v.
 func (j grpcJson) Unmarshal(data []byte, v interface{}) (err error) {
 	if pm, ok := v.(proto.Message); ok {
 		b := bytes.NewBuffer(data)
diff --git a/protocol/grpc/config.go b/protocol/grpc/config.go
index 529b6068c9f708ff7af92ec58abd4cf6bb8c8b10..e8a9baac8999a009bab435a5bd4e70d102f77b56 100644
--- a/protocol/grpc/config.go
+++ b/protocol/grpc/config.go
@@ -22,44 +22,44 @@ import (
 )
 
 type (
-	// ServerConfig
+	// ServerConfig currently is empty struct,for future expansion
 	ServerConfig struct {
 	}
 
-	// ClientConfig
+	// ClientConfig wrap client call parameters
 	ClientConfig struct {
 		// content type, more information refer by https://github.com/grpc/grpc/blob/master/doc/PROTOCOL-HTTP2.md#requests
 		ContentSubType string `default:"proto" yaml:"content_sub_type" json:"content_sub_type,omitempty"`
 	}
 )
 
-// GetDefaultClientConfig ...
+// GetDefaultClientConfig return grpc client default call options
 func GetDefaultClientConfig() ClientConfig {
 	return ClientConfig{
-		ContentSubType: CODEC_PROTO,
+		ContentSubType: codecProto,
 	}
 }
 
-// GetDefaultServerConfig ...
+// GetDefaultServerConfig currently return empty struct,for future expansion
 func GetDefaultServerConfig() ServerConfig {
 	return ServerConfig{}
 }
 
-// GetClientConfig ...
+// GetClientConfig return grpc client custom call options
 func GetClientConfig() ClientConfig {
 	return ClientConfig{}
 }
 
-// clientConfig Validate ...
+// Validate check if custom config encoding is supported in dubbo grpc
 func (c *ClientConfig) Validate() error {
-	if c.ContentSubType != CODEC_JSON && c.ContentSubType != CODEC_PROTO {
+	if c.ContentSubType != codecJson && c.ContentSubType != codecProto {
 		return perrors.Errorf(" dubbo-go grpc codec currently only support proto銆乯son, %s isn't supported,"+
 			" please check protocol content_sub_type config", c.ContentSubType)
 	}
 	return nil
 }
 
-// severConfig Validate ...
+// Validate currently return empty struct,for future expansion
 func (c *ServerConfig) Validate() error {
 	return nil
 }