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 7a6e4724..2fb0aa82 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
@@ -358,7 +358,11 @@ export class OrganizationComponent implements OnInit, OnDestroy {
           })
         );
 
-        this.selectedUserList = [];
+        // 상위 컴포넌트의 selectedUserList clear.
+        this.checkAllUser.emit({
+          isChecked: false,
+          userInfos: this.selectedUserList
+        });
       }
     }
   }
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 237c9cef..e4f66abc 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
@@ -35,8 +35,17 @@
           <mat-tab>
             <ng-template mat-tab-label>
               <!--<mat-icon>group</mat-icon>-->
-              <svg xmlns="http://www.w3.org/2000/svg" width="20" height="20" viewBox="0 0 24 24" fill="none" stroke="currentColor"
-                stroke-width="1.5" stroke-linecap="butt" stroke-linejoin="round">
+              <svg
+                xmlns="http://www.w3.org/2000/svg"
+                width="20"
+                height="20"
+                viewBox="0 0 24 24"
+                fill="none"
+                stroke="currentColor"
+                stroke-width="1.5"
+                stroke-linecap="butt"
+                stroke-linejoin="round"
+              >
                 <path d="M17 21v-2a4 4 0 0 0-4-4H5a4 4 0 0 0-4 4v2"></path>
                 <circle cx="9" cy="7" r="4"></circle>
                 <path d="M23 21v-2a4 4 0 0 0-3-3.87"></path>
@@ -54,29 +63,38 @@
                   (cancel)="onClickCancel()"
                 ></ucap-organization-tenant-search>
               </div>
-              <div *ngIf="!isShowSearch" class="list-panel">
-                <ucap-group-expansion-panel
-                  #groupExpansionPanel
-                  [groupBuddyList]="groupBuddyList$ | async"
-                  [favoritBuddyList]="favoritBuddyList$ | async"
-                  [selectedUserList]="selectedUserList"
-                  [checkable]="true"
-                  (checkGroup)="onCheckGroup($event)"
-                  class="group-expansion"
-                >
-                  <ucap-profile-user-list-item
-                    *ucapGroupExpansionPanelItem="let userInfo"
-                    [userInfo]="userInfo"
-                    [sessionVerinfo]="sessionVerinfo"
+              <div
+                [style.display]="isShowSearch ? 'none' : 'block'"
+                class="list-panel"
+                style="overflow: auto;"
+              >
+                <perfect-scrollbar>
+                  <ucap-group-expansion-panel
+                    #groupExpansionPanel
+                    [groupBuddyList]="groupBuddyList$ | async"
+                    [favoritBuddyList]="favoritBuddyList$ | async"
                     [selectedUserList]="selectedUserList"
-                    [isChecked]="getCheckedUser(userInfo)"
                     [checkable]="true"
-                    (checkUser)="onCheckUser($event)"
+                    (checkGroup)="onCheckGroup($event)"
+                    class="group-expansion"
                   >
-                  </ucap-profile-user-list-item>
-                </ucap-group-expansion-panel>
+                    <ucap-profile-user-list-item
+                      *ucapGroupExpansionPanelItem="let userInfo"
+                      [userInfo]="userInfo"
+                      [sessionVerinfo]="sessionVerinfo"
+                      [selectedUserList]="selectedUserList"
+                      [isChecked]="getCheckedUser(userInfo)"
+                      [checkable]="true"
+                      (checkUser)="onCheckUser($event)"
+                    >
+                    </ucap-profile-user-list-item>
+                  </ucap-group-expansion-panel>
+                </perfect-scrollbar>
               </div>
-              <div *ngIf="isShowSearch" class="search-result">
+              <div
+                [style.display]="isShowSearch ? 'block' : 'none'"
+                class="search-result"
+              >
                 <div *ngIf="searchProcessing">
                   <mat-progress-bar mode="indeterminate"></mat-progress-bar>
                 </div>