diff --git a/projects/ucap-webmessenger-app/src/app/layouts/messenger/components/left-sidenav/organization.component.html b/projects/ucap-webmessenger-app/src/app/layouts/messenger/components/left-sidenav/organization.component.html
index 6c753ed0..0b8a1051 100644
--- a/projects/ucap-webmessenger-app/src/app/layouts/messenger/components/left-sidenav/organization.component.html
+++ b/projects/ucap-webmessenger-app/src/app/layouts/messenger/components/left-sidenav/organization.component.html
@@ -59,9 +59,10 @@
         <ucap-profile-user-list-item
           *cdkVirtualFor="let userInfo of selectedDepartmentUserInfoList"
           [userInfo]="userInfo"
-          [checkable]="true"
           [sessionVerinfo]="sessionVerinfo"
           [selectedUserList]="selectedUserList"
+          [checkable]="true"
+          [checkDisabled]="!getCheckableUser(userInfo)"
           [isChecked]="getCheckedUser(userInfo)"
           (checkUser)="onCheckUser($event)"
           (openProfile)="onClickOpenProfile($event)"
diff --git a/projects/ucap-webmessenger-app/src/app/layouts/messenger/components/left-sidenav/organization.component.ts b/projects/ucap-webmessenger-app/src/app/layouts/messenger/components/left-sidenav/organization.component.ts
index 1f29064b..55e30ecb 100644
--- a/projects/ucap-webmessenger-app/src/app/layouts/messenger/components/left-sidenav/organization.component.ts
+++ b/projects/ucap-webmessenger-app/src/app/layouts/messenger/components/left-sidenav/organization.component.ts
@@ -6,8 +6,6 @@ import {
   EventEmitter,
   Input,
   ViewChild,
-  AfterViewInit,
-  AfterContentChecked,
   AfterViewChecked
 } from '@angular/core';
 import { ucapAnimations, DialogService } from '@ucap-webmessenger/ui';
@@ -65,6 +63,9 @@ export class OrganizationComponent
   /** 선택된 사용자의 리스트 */
   selectedUserList?: (UserInfo | UserInfoSS | UserInfoF | UserInfoDN)[] = [];
   @Input()
+  /** 선택할 수 없는 사용자 리스트 */
+  ignoreUserList?: (UserInfo | UserInfoSS | UserInfoF | UserInfoDN)[] = [];
+  @Input()
   isVisible = true;
 
   @Output()
@@ -339,6 +340,17 @@ export class OrganizationComponent
       return true;
     }
   }
+  /** ignoreUserList(선택 무시할 인원) 이 있을 경우 판단하여 checkable 판단. */
+  getCheckableUser(userInfo: UserInfo | UserInfoSS | UserInfoF | UserInfoDN) {
+    if (
+      !!this.ignoreUserList &&
+      this.ignoreUserList.filter(user => user.seq === userInfo.seq).length > 0
+    ) {
+      return false;
+    }
+
+    return true;
+  }
   /** 리스트 checkable 할 경우 checkbox 의 isChecked 를 관장하며 리스트의 전체선택 여부를 판단한다. */
   getCheckedUser(userInfo: UserInfo | UserInfoSS | UserInfoF | UserInfoDN) {
     if (!!this.selectedUserList && this.selectedUserList.length > 0) {
diff --git a/projects/ucap-webmessenger-app/src/app/layouts/messenger/dialogs/chat/create-chat.dialog.component.html b/projects/ucap-webmessenger-app/src/app/layouts/messenger/dialogs/chat/create-chat.dialog.component.html
index bbe569a9..676860a9 100644
--- a/projects/ucap-webmessenger-app/src/app/layouts/messenger/dialogs/chat/create-chat.dialog.component.html
+++ b/projects/ucap-webmessenger-app/src/app/layouts/messenger/dialogs/chat/create-chat.dialog.component.html
@@ -73,6 +73,7 @@
                   #groupExpansionPanel
                   [groupBuddyList]="groupBuddyList$ | async"
                   [selectedUserList]="selectedUserList"
+                  [ignoreUserList]="data.curRoomUser"
                   [checkable]="true"
                   (checkGroup)="onCheckGroup($event)"
                   class="group-expansion"
@@ -84,6 +85,7 @@
                     [selectedUserList]="selectedUserList"
                     [isChecked]="getCheckedUser(userInfo)"
                     [checkable]="true"
+                    [checkDisabled]="!getCheckableUser(userInfo)"
                     (checkUser)="onCheckUser($event)"
                     (click)="onToggleUser(userInfo)"
                     class="list-item-frame"
@@ -117,6 +119,7 @@
                   [selectedUserList]="selectedUserList"
                   [isChecked]="getCheckedUser(userInfo)"
                   [checkable]="true"
+                  [checkDisabled]="!getCheckableUser(userInfo)"
                   (checkUser)="onCheckUser($event)"
                   (click)="onToggleUser(userInfo)"
                 >
@@ -134,6 +137,7 @@
               <app-layout-chat-left-sidenav-organization
                 [showTitle]="false"
                 [selectedUserList]="selectedUserList"
+                [ignoreUserList]="data.curRoomUser"
                 [isUserSelect]="true"
                 [isVisible]="currentTabIndex === 1"
                 (checkAllUser)="onCheckAllUser($event)"
diff --git a/projects/ucap-webmessenger-app/src/app/layouts/messenger/dialogs/chat/create-chat.dialog.component.ts b/projects/ucap-webmessenger-app/src/app/layouts/messenger/dialogs/chat/create-chat.dialog.component.ts
index 16fc7fdd..78035c6c 100644
--- a/projects/ucap-webmessenger-app/src/app/layouts/messenger/dialogs/chat/create-chat.dialog.component.ts
+++ b/projects/ucap-webmessenger-app/src/app/layouts/messenger/dialogs/chat/create-chat.dialog.component.ts
@@ -63,7 +63,7 @@ export interface CreateChatDialogData {
   group?: GroupDetailData;
   /** CASE :: EventForward */
   ignoreRoom?: RoomInfo[];
-  /** CASE :: EditCharMember */
+  /** CASE :: EditChatMember */
   curRoomUser?: (
     | UserInfo
     | UserInfoSS
@@ -367,20 +367,47 @@ export class CreateChatDialogComponent implements OnInit, OnDestroy {
     groupBuddyList: { group: GroupDetailData; buddyList: UserInfo[] };
   }) {
     if (params.isChecked) {
-      params.groupBuddyList.buddyList.forEach(item => {
-        if (
-          this.selectedUserList.filter(user => user.seq === item.seq).length ===
-          0
-        ) {
-          this.selectedUserList = [...this.selectedUserList, item];
-        }
-      });
+      if (this.data.type === UserSelectDialogType.EditChatMember) {
+        params.groupBuddyList.buddyList.forEach(item => {
+          if (
+            this.selectedUserList.filter(user => user.seq === item.seq)
+              .length === 0 &&
+            this.data.curRoomUser.filter(curUser => curUser.seq === item.seq)
+              .length === 0
+          ) {
+            this.selectedUserList = [...this.selectedUserList, item];
+          }
+        });
+      } else {
+        params.groupBuddyList.buddyList.forEach(item => {
+          if (
+            this.selectedUserList.filter(user => user.seq === item.seq)
+              .length === 0
+          ) {
+            this.selectedUserList = [...this.selectedUserList, item];
+          }
+        });
+      }
     } else {
-      this.selectedUserList = this.selectedUserList.filter(
-        item =>
-          params.groupBuddyList.buddyList.filter(del => del.seq === item.seq)
-            .length === 0
-      );
+      if (this.data.type === UserSelectDialogType.EditChatMember) {
+        this.selectedUserList = this.selectedUserList.filter(
+          item =>
+            params.groupBuddyList.buddyList
+              .filter(
+                del =>
+                  this.data.curRoomUser.filter(
+                    curUser => curUser.seq === del.seq
+                  ).length === 0
+              )
+              .filter(del => del.seq === item.seq).length === 0
+        );
+      } else {
+        this.selectedUserList = this.selectedUserList.filter(
+          item =>
+            params.groupBuddyList.buddyList.filter(del => del.seq === item.seq)
+              .length === 0
+        );
+      }
     }
     this.changeDetectorRef.detectChanges();
   }
@@ -390,20 +417,51 @@ export class CreateChatDialogComponent implements OnInit, OnDestroy {
     isChecked: boolean;
     userInfos: (UserInfo | UserInfoSS | UserInfoF | UserInfoDN)[];
   }) {
-    params.userInfos.forEach(userInfo => {
-      if (params.isChecked) {
-        if (
-          this.selectedUserList.filter(user => user.seq === userInfo.seq)
-            .length === 0
-        ) {
-          this.selectedUserList = [...this.selectedUserList, userInfo];
-        }
+    // params.userInfos.forEach(userInfo => {
+    if (params.isChecked) {
+      if (this.data.type === UserSelectDialogType.EditChatMember) {
+        params.userInfos.forEach(item => {
+          if (
+            this.selectedUserList.filter(user => user.seq === item.seq)
+              .length === 0 &&
+            this.data.curRoomUser.filter(curUser => curUser.seq === item.seq)
+              .length === 0
+          ) {
+            this.selectedUserList = [...this.selectedUserList, item];
+          }
+        });
+      } else {
+        params.userInfos.forEach(item => {
+          if (
+            this.selectedUserList.filter(user => user.seq === item.seq)
+              .length === 0
+          ) {
+            this.selectedUserList = [...this.selectedUserList, item];
+          }
+        });
+      }
+    } else {
+      if (this.data.type === UserSelectDialogType.EditChatMember) {
+        this.selectedUserList = this.selectedUserList.filter(
+          item =>
+            params.userInfos
+              .filter(
+                del =>
+                  this.data.curRoomUser.filter(
+                    curUser => curUser.seq === del.seq
+                  ).length === 0
+              )
+              .filter(del => del.seq === item.seq).length === 0
+        );
       } else {
         this.selectedUserList = this.selectedUserList.filter(
-          user => user.seq !== userInfo.seq
+          item =>
+            params.userInfos.filter(userInfo => userInfo.seq === item.seq)
+              .length === 0
         );
       }
-    });
+    }
+    // });
   }
 
   /** 동료그룹>부서원, 조직도>부서원 :: 리스트의 checkbox 의 이벤트를 받아 선택된 유저리스트를 수집. */
@@ -412,6 +470,15 @@ export class CreateChatDialogComponent implements OnInit, OnDestroy {
     userInfo: UserInfo | UserInfoSS | UserInfoF | UserInfoDN;
   }) {
     if (params.isChecked) {
+      if (this.data.type === UserSelectDialogType.EditChatMember) {
+        if (
+          this.data.curRoomUser.filter(user => user.seq === params.userInfo.seq)
+            .length > 0
+        ) {
+          return;
+        }
+      }
+
       if (
         this.selectedUserList.filter(user => user.seq === params.userInfo.seq)
           .length === 0 &&
@@ -420,6 +487,15 @@ export class CreateChatDialogComponent implements OnInit, OnDestroy {
         this.selectedUserList = [...this.selectedUserList, params.userInfo];
       }
     } else {
+      if (this.data.type === UserSelectDialogType.EditChatMember) {
+        if (
+          this.data.curRoomUser.filter(user => user.seq === params.userInfo.seq)
+            .length > 0
+        ) {
+          return;
+        }
+      }
+
       this.selectedUserList = this.selectedUserList.filter(
         item => item.seq !== params.userInfo.seq
       );
@@ -427,6 +503,15 @@ export class CreateChatDialogComponent implements OnInit, OnDestroy {
     this.changeDetectorRef.detectChanges();
   }
   onToggleUser(userInfo: UserInfo | UserInfoSS | UserInfoF | UserInfoDN) {
+    if (this.data.type === UserSelectDialogType.EditChatMember) {
+      if (
+        this.data.curRoomUser.filter(user => user.seq === userInfo.seq).length >
+        0
+      ) {
+        return;
+      }
+    }
+
     if (
       this.selectedUserList.filter(user => user.seq === userInfo.seq).length ===
       0
@@ -459,6 +544,20 @@ export class CreateChatDialogComponent implements OnInit, OnDestroy {
     }
   }
 
+  /** 그룹>부서원의 체크 가능여부 판단. */
+  getCheckableUser(userInfo: UserInfo | UserInfoSS | UserInfoF | UserInfoDN) {
+    if (this.data.type === UserSelectDialogType.EditChatMember) {
+      if (
+        this.data.curRoomUser.filter(user => user.seq === userInfo.seq).length >
+        0
+      ) {
+        return false;
+      }
+    }
+
+    return true;
+  }
+
   /** 그룹>부서원 리스트의 ischecked 를 판단. */
   getCheckedUser(userInfo: UserInfo | UserInfoSS | UserInfoF | UserInfoDN) {
     if (!!this.selectedUserList && this.selectedUserList.length > 0) {
diff --git a/projects/ucap-webmessenger-ui-group/src/lib/components/expansion-panel.component.html b/projects/ucap-webmessenger-ui-group/src/lib/components/expansion-panel.component.html
index f08ca10c..346122ae 100644
--- a/projects/ucap-webmessenger-ui-group/src/lib/components/expansion-panel.component.html
+++ b/projects/ucap-webmessenger-ui-group/src/lib/components/expansion-panel.component.html
@@ -76,6 +76,7 @@
             *ngIf="checkable"
             #checkbox
             [checked]="getCheckedGroup(node.groupDetail)"
+            [disabled]="!getCheckableGroup(node.groupDetail)"
             (change)="onChangeCheck(checkbox.checked, node.groupDetail)"
             (click)="$event.stopPropagation()"
             class="group-check"
diff --git a/projects/ucap-webmessenger-ui-group/src/lib/components/expansion-panel.component.ts b/projects/ucap-webmessenger-ui-group/src/lib/components/expansion-panel.component.ts
index 77fe47a6..471f50fb 100644
--- a/projects/ucap-webmessenger-ui-group/src/lib/components/expansion-panel.component.ts
+++ b/projects/ucap-webmessenger-ui-group/src/lib/components/expansion-panel.component.ts
@@ -135,10 +135,12 @@ export class ExpansionPanelComponent
 
   @Input()
   checkable = false;
-
   @Input()
   /** 선택된 사용자의 리스트 */
   selectedUserList?: (UserInfo | UserInfoSS | UserInfoF | UserInfoDN)[] = [];
+  @Input()
+  /** 선택할 수 없는 사용자 리스트 */
+  ignoreUserList?: (UserInfo | UserInfoSS | UserInfoF | UserInfoDN)[] = [];
 
   @Output()
   more = new EventEmitter<{
@@ -270,6 +272,24 @@ export class ExpansionPanelComponent
     }
   }
 
+  getCheckableGroup(group: GroupDetailData) {
+    if (!!this.ignoreUserList && this.ignoreUserList.length > 0) {
+      let allExist = true;
+      group.userSeqs.some(seq => {
+        if (this.ignoreUserList.filter(item => item.seq === seq).length === 0) {
+          allExist = false;
+          return true;
+        }
+      });
+
+      if (allExist) {
+        return false;
+      }
+    }
+
+    return true;
+  }
+
   /** 그룹리스트가 checkable 할 경우 checkbox 의 isChecked 를 관장하며, 하위 부서원들의 전체선택여부를 판단한다. */
   getCheckedGroup(group: GroupDetailData) {
     if (!group || group === undefined) {
diff --git a/projects/ucap-webmessenger-ui-profile/src/lib/components/user-list-item.component.html b/projects/ucap-webmessenger-ui-profile/src/lib/components/user-list-item.component.html
index d68dcd83..b27cc911 100644
--- a/projects/ucap-webmessenger-ui-profile/src/lib/components/user-list-item.component.html
+++ b/projects/ucap-webmessenger-ui-profile/src/lib/components/user-list-item.component.html
@@ -36,6 +36,7 @@
     *ngIf="checkable"
     #checkbox
     [checked]="isChecked"
+    [disabled]="checkDisabled"
     (change)="onChangeCheck(checkbox.checked, userInfo)"
     (click)="$event.stopPropagation()"
   >
diff --git a/projects/ucap-webmessenger-ui-profile/src/lib/components/user-list-item.component.ts b/projects/ucap-webmessenger-ui-profile/src/lib/components/user-list-item.component.ts
index 1b56f947..28d5212d 100644
--- a/projects/ucap-webmessenger-ui-profile/src/lib/components/user-list-item.component.ts
+++ b/projects/ucap-webmessenger-ui-profile/src/lib/components/user-list-item.component.ts
@@ -35,6 +35,8 @@ export class UserListItemComponent implements OnInit {
   @Input()
   checkable = false;
   @Input()
+  checkDisabled = false;
+  @Input()
   isChecked = false;
   @Input()
   compactable = false;