diff --git a/projects/ucap-webmessenger-protocol-group/src/lib/models/group-add.ts b/projects/ucap-webmessenger-protocol-group/src/lib/models/group-add.ts
new file mode 100644
index 00000000..0a6a51e4
--- /dev/null
+++ b/projects/ucap-webmessenger-protocol-group/src/lib/models/group-add.ts
@@ -0,0 +1,41 @@
+import { DeviceType, LocaleCode } from '@ucap-webmessenger/core';
+import {
+  ProtocolRequest,
+  ProtocolResponse,
+  ProtocolEncoder,
+  PacketBody,
+  PacketBodyValue,
+  ProtocolDecoder,
+  ProtocolMessage
+} from '@ucap-webmessenger/protocol';
+
+export interface GroupAddRequest extends ProtocolRequest {
+  // 0. 동료그룹이름
+  groupName: string;
+}
+
+export interface GroupAddResponse extends ProtocolResponse {
+  // 0: 동료그룹SEQ(n)
+  groupSeq: number;
+  // 1: 동료그룹이름(s)
+  groupName: string;
+}
+
+export const encodeGroupAdd: ProtocolEncoder<GroupAddRequest> = (
+  req: GroupAddRequest
+) => {
+  const bodyList: PacketBody[] = [];
+
+  bodyList.push({ type: PacketBodyValue.String, value: req.groupName });
+
+  return bodyList;
+};
+
+export const decodeGroupAdd: ProtocolDecoder<GroupAddResponse> = (
+  message: ProtocolMessage
+) => {
+  return {
+    groupSeq: message.bodyList[0],
+    groupName: message.bodyList[1]
+  } as GroupAddResponse;
+};
diff --git a/projects/ucap-webmessenger-protocol-group/src/lib/models/group-del.ts b/projects/ucap-webmessenger-protocol-group/src/lib/models/group-del.ts
new file mode 100644
index 00000000..1612aa6b
--- /dev/null
+++ b/projects/ucap-webmessenger-protocol-group/src/lib/models/group-del.ts
@@ -0,0 +1,38 @@
+import { DeviceType, LocaleCode } from '@ucap-webmessenger/core';
+import {
+  ProtocolRequest,
+  ProtocolResponse,
+  ProtocolEncoder,
+  PacketBody,
+  PacketBodyValue,
+  ProtocolDecoder,
+  ProtocolMessage
+} from '@ucap-webmessenger/protocol';
+
+export interface GroupDelRequest extends ProtocolRequest {
+  // 0: 동료그룹SEQ(n)
+  groupSeq: number;
+}
+
+export interface GroupDelResponse extends ProtocolResponse {
+  // 0: 동료그룹SEQ(n)
+  groupSeq: number;
+}
+
+export const encodeGroupDel: ProtocolEncoder<GroupDelRequest> = (
+  req: GroupDelRequest
+) => {
+  const bodyList: PacketBody[] = [];
+
+  bodyList.push({ type: PacketBodyValue.Integer, value: req.groupSeq });
+
+  return bodyList;
+};
+
+export const decodeGroupDel: ProtocolDecoder<GroupDelResponse> = (
+  message: ProtocolMessage
+) => {
+  return {
+    groupSeq: message.bodyList[0]
+  } as GroupDelResponse;
+};
diff --git a/projects/ucap-webmessenger-protocol-group/src/lib/models/group-update.ts b/projects/ucap-webmessenger-protocol-group/src/lib/models/group-update.ts
new file mode 100644
index 00000000..ba28ad7e
--- /dev/null
+++ b/projects/ucap-webmessenger-protocol-group/src/lib/models/group-update.ts
@@ -0,0 +1,91 @@
+import { DeviceType, LocaleCode } from '@ucap-webmessenger/core';
+import {
+  ProtocolRequest,
+  ProtocolResponse,
+  ProtocolEncoder,
+  PacketBody,
+  PacketBodyValue,
+  ProtocolDecoder,
+  ProtocolMessage
+} from '@ucap-webmessenger/protocol';
+
+export interface GroupUpdateRequest extends ProtocolRequest {
+  // 0: 동료그룹SEQ(n)
+  groupSeq: number;
+  // 1: 동료그룹이름(s)
+  groupName: string;
+  // 2n: 사용자SEQ(n)...
+  userSeqs: [];
+}
+
+export interface GroupUpdateResponse extends ProtocolResponse {
+  // 0: 동료그룹SEQ(n)
+  groupSeq: number;
+  // 1: 동료그룹이름(s)
+  groupName: string;
+  // 2n: 사용자SEQ(n)...
+  userSeqs: [];
+}
+
+export const encodeGroupUpdate: ProtocolEncoder<GroupUpdateRequest> = (
+  req: GroupUpdateRequest
+) => {
+  const bodyList: PacketBody[] = [];
+
+  bodyList.push(
+    { type: PacketBodyValue.Integer, value: req.groupSeq },
+    { type: PacketBodyValue.String, value: req.groupName },
+    { type: PacketBodyValue.String, value: req.userSeqs.join() }
+  );
+
+  return bodyList;
+};
+
+export const decodeGroupUpdate: ProtocolDecoder<GroupUpdateResponse> = (
+  message: ProtocolMessage
+) => {
+  let userSeqArray: Array<number> = [];
+  if (message.bodyList.length > 2 && !message.bodyList[2].empty()) {
+    userSeqArray = message.bodyList[2].split(',').map(v => Number(v));
+  }
+
+  return {
+    groupSeq: message.bodyList[0],
+    groupName: message.bodyList[1],
+    userSeqs: userSeqArray
+  } as GroupUpdateResponse;
+};
+
+export const encodeGroupUpdate2: ProtocolEncoder<GroupUpdateRequest> = (
+  req: GroupUpdateRequest
+) => {
+  const bodyList: PacketBody[] = [];
+
+  bodyList.push(
+    { type: PacketBodyValue.Integer, value: req.groupSeq },
+    { type: PacketBodyValue.String, value: req.groupName }
+  );
+
+  if (req.userSeqs.length > 0) {
+    req.userSeqs.forEach(userSeq => {
+      bodyList.push({ type: PacketBodyValue.Integer, value: userSeq });
+    });
+  }
+
+  return bodyList;
+};
+
+export const decodeGroupUpdate2: ProtocolDecoder<GroupUpdateResponse> = (
+  message: ProtocolMessage
+) => {
+  let userSeqArray: Array<number> = [];
+  if (message.bodyList.length > 2) {
+    userSeqArray = message.bodyList.slice(2);
+  }
+
+  return {
+    groupSeq: message.bodyList[0],
+    groupName: message.bodyList[1],
+    userSeqs: userSeqArray
+  } as GroupUpdateResponse;
+};
diff --git a/projects/ucap-webmessenger-protocol-group/src/lib/services/group-protocol.service.ts b/projects/ucap-webmessenger-protocol-group/src/lib/services/group-protocol.service.ts
index 20714e3c..59667652 100644
--- a/projects/ucap-webmessenger-protocol-group/src/lib/services/group-protocol.service.ts
+++ b/projects/ucap-webmessenger-protocol-group/src/lib/services/group-protocol.service.ts
@@ -1,8 +1,64 @@
 import { Injectable } from '@angular/core';
 
+import { Observable } from 'rxjs';
+import { map } from 'rxjs/operators';
+
+import { ProtocolService } from '@ucap-webmessenger/protocol';
+import {
+  GroupAddRequest,
+  encodeGroupAdd,
+  decodeGroupAdd
+} from '../models/group-add';
+import {
+  SVC_TYPE_GROUP,
+  SSVC_TYPE_GROUP_ADD_REQ,
+  SSVC_TYPE_GROUP_DEL_REQ,
+  SSVC_TYPE_GROUP_UPD_REQ,
+  SSVC_TYPE_GROUP_UPD_REQ2
+} from '../types/service';
+import {
+  GroupDelRequest,
+  encodeGroupDel,
+  decodeGroupDel
+} from '../models/group-del';
+import {
+  GroupUpdateRequest,
+  encodeGroupUpdate,
+  decodeGroupUpdate,
+  encodeGroupUpdate2,
+  decodeGroupUpdate2
+} from '../models/group-update';
 @Injectable({
   providedIn: 'root'
 })
 export class GroupProtocolService {
-  constructor() {}
+  constructor(private protocolService: ProtocolService) {}
+
+  public groupAdd(req: GroupAddRequest): Observable<GroupAddRequest> {
+    return this.protocolService
+      .call(SVC_TYPE_GROUP, SSVC_TYPE_GROUP_ADD_REQ, ...encodeGroupAdd(req))
+      .pipe(map(res => decodeGroupAdd(res)));
+  }
+
+  public groupDel(req: GroupDelRequest): Observable<GroupDelRequest> {
+    return this.protocolService
+      .call(SVC_TYPE_GROUP, SSVC_TYPE_GROUP_DEL_REQ, ...encodeGroupDel(req))
+      .pipe(map(res => decodeGroupDel(res)));
+  }
+
+  public groupUpdate(req: GroupUpdateRequest): Observable<GroupUpdateRequest> {
+    return this.protocolService
+      .call(SVC_TYPE_GROUP, SSVC_TYPE_GROUP_UPD_REQ, ...encodeGroupUpdate(req))
+      .pipe(map(res => decodeGroupUpdate(res)));
+  }
+
+  public groupUpdate2(req: GroupUpdateRequest): Observable<GroupUpdateRequest> {
+    return this.protocolService
+      .call(
+        SVC_TYPE_GROUP,
+        SSVC_TYPE_GROUP_UPD_REQ2,
+        ...encodeGroupUpdate2(req)
+      )
+      .pipe(map(res => decodeGroupUpdate2(res)));
+  }
 }
diff --git a/projects/ucap-webmessenger-protocol-group/src/lib/types/service.ts b/projects/ucap-webmessenger-protocol-group/src/lib/types/service.ts
new file mode 100644
index 00000000..f986c8b2
--- /dev/null
+++ b/projects/ucap-webmessenger-protocol-group/src/lib/types/service.ts
@@ -0,0 +1,9 @@
+export const SVC_TYPE_GROUP = 5; // 동료 그룹 관리
+export const SSVC_TYPE_GROUP_ADD_REQ = 1; // 동료 그룹 추가
+export const SSVC_TYPE_GROUP_ADD_RES = 2;
+export const SSVC_TYPE_GROUP_DEL_REQ = 11; // 동료 그룹 삭제
+export const SSVC_TYPE_GROUP_DEL_RES = 12;
+export const SSVC_TYPE_GROUP_UPD_REQ = 21; // 동료 그룹 변경
+export const SSVC_TYPE_GROUP_UPD_RES = 22;
+export const SSVC_TYPE_GROUP_UPD_REQ2 = 23;
+export const SSVC_TYPE_GROUP_UPD_RES2 = 24;