diff --git a/server/client.go b/server/client.go
index 9981207..2fa70cd 100644
--- a/server/client.go
+++ b/server/client.go
@@ -186,7 +186,8 @@ func (c *client) onMessageReceived(messageType int, r io.Reader) {
 	grpcClient := grpcPool.(serverGrpc.OverflowApiServerClient)
 	out, err := grpcClient.Exec(context.Background(), si)
 	if err != nil {
-		c.writeError(req, NewError(E_SERVER, err, err))
+		c.writeError(req, NewGrpcError(err))
+		return
 	}
 
 	c.writeResult(req, out.Result)
diff --git a/server/protocol.go b/server/protocol.go
index 24217c6..f81bd42 100644
--- a/server/protocol.go
+++ b/server/protocol.go
@@ -3,17 +3,22 @@ package server
 import (
 	"encoding/json"
 	"errors"
+
+	grpcCodes "google.golang.org/grpc/codes"
+	grpcStatus "google.golang.org/grpc/status"
 )
 
 type ErrorCode int
 
 const (
+	E_RUNTIME          ErrorCode = -33000
 	E_PARSE            ErrorCode = -32700
 	E_INVALID_REQ      ErrorCode = -32600
 	E_NOT_FOUND_METHOD ErrorCode = -32601
 	E_INVALID_PARAMS   ErrorCode = -32602
 	E_INTERNAL         ErrorCode = -32603
-	E_SERVER           ErrorCode = -32000
+	// -32000 ~ -32099
+	E_SERVER ErrorCode = -32000
 )
 
 var ErrNullResult = errors.New("result is null")
@@ -48,3 +53,34 @@ func NewError(code ErrorCode, err error, data interface{}) *Error {
 	}
 	return e
 }
+
+func NewGrpcError(err error) *Error {
+	resultStatus, ok := grpcStatus.FromError(err)
+	if !ok {
+		return nil
+	}
+
+	var code ErrorCode
+
+	switch resultStatus.Code() {
+	case grpcCodes.Unknown:
+		code = E_RUNTIME
+	case grpcCodes.InvalidArgument:
+		code = E_INVALID_PARAMS
+	case grpcCodes.Internal:
+		code = E_INTERNAL
+	case grpcCodes.Unimplemented:
+		code = E_NOT_FOUND_METHOD
+	case grpcCodes.Unavailable:
+		code = E_NOT_FOUND_METHOD
+	default:
+
+	}
+
+	e := &Error{
+		Code:    code,
+		Message: resultStatus.Message(),
+		Data:    nil,
+	}
+	return e
+}