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 0c77d7da..6585124d 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
@@ -15,6 +15,7 @@
     <ucap-organization-tree
       [oraganizationList]="departmentInfoList$ | async"
       [loginRes]="loginRes"
+      [activate$]="gnbMenuChangedSubject.asObservable()"
       (selected)="onSelectedOrganization($event)"
       class="tab-tree-frame"
     ></ucap-organization-tree>
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 37427654..892aba33 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
@@ -10,7 +10,7 @@ import {
   ChangeDetectorRef
 } from '@angular/core';
 import { ucapAnimations, DialogService } from '@ucap-webmessenger/ui';
-import { Observable, Subscription, of } from 'rxjs';
+import { Observable, Subscription, of, BehaviorSubject } from 'rxjs';
 import {
   DeptInfo,
   QueryProtocolService,
@@ -40,7 +40,8 @@ import {
   KEY_VER_INFO,
   EnvironmentsInfo,
   KEY_ENVIRONMENTS_INFO,
-  KEY_AUTH_INFO
+  KEY_AUTH_INFO,
+  MainMenu
 } from '@app/types';
 import { take, map, tap, delay, catchError } from 'rxjs/operators';
 import { VersionInfo2Response } from '@ucap-webmessenger/api-public';
@@ -154,6 +155,11 @@ export class OrganizationComponent
   isShowSearch = false;
   searchUserInfos: UserInfoSS[] = [];
 
+  gnbMenuChangedSubject: BehaviorSubject<boolean> = new BehaviorSubject<
+    boolean
+  >(false);
+  gnbMenuChangedSubscription: Subscription;
+
   /** 부서원 리스트에 virture scroll의 size 가 체킹되지 않아 강제 수행. 1번만. */
   isInitList = false;
 
@@ -256,6 +262,12 @@ export class OrganizationComponent
           this.psDirectiveRef.update();
         }
       });
+
+    this.gnbMenuChangedSubscription = this.store
+      .pipe(select(AppStore.MessengerSelector.SettingsSelector.gnbMenuIndex))
+      .subscribe(menu => {
+        this.gnbMenuChangedSubject.next(menu === MainMenu.Organization);
+      });
   }
 
   ngAfterViewChecked(): void {
@@ -277,6 +289,9 @@ export class OrganizationComponent
     if (!!this.myDepartmentUserInfoListSubscription) {
       this.myDepartmentUserInfoListSubscription.unsubscribe();
     }
+    if (!!this.gnbMenuChangedSubscription) {
+      this.gnbMenuChangedSubscription.unsubscribe();
+    }
   }
 
   /** 유저검색 */
diff --git a/projects/ucap-webmessenger-ui-organization/src/lib/components/tree.component.ts b/projects/ucap-webmessenger-ui-organization/src/lib/components/tree.component.ts
index 57cc3bf8..2bba954f 100644
--- a/projects/ucap-webmessenger-ui-organization/src/lib/components/tree.component.ts
+++ b/projects/ucap-webmessenger-ui-organization/src/lib/components/tree.component.ts
@@ -20,7 +20,7 @@ import { VirtualScrollTreeFlatDataSource } from '@ucap-webmessenger/ui';
 import { ucapAnimations } from '@ucap-webmessenger/ui';
 import { trigger, transition, style, animate } from '@angular/animations';
 import { PerfectScrollbarDirective } from 'ngx-perfect-scrollbar';
-import { Subscription } from 'rxjs';
+import { Subscription, Observable } from 'rxjs';
 
 interface OrganizationNode {
   deptInfo: DeptInfo;
@@ -103,6 +103,9 @@ export class TreeComponent implements OnInit, OnDestroy, AfterViewInit {
     this.dataSource.data = rootNodeList;
   }
 
+  @Input()
+  activate$: Observable<boolean>;
+
   @Output()
   selected = new EventEmitter<DeptInfo>();
 
@@ -121,6 +124,8 @@ export class TreeComponent implements OnInit, OnDestroy, AfterViewInit {
 
   treeControlExpansionChangeSubscription: Subscription;
 
+  activateSubscription: Subscription;
+
   constructor(
     private changeDetectorRef: ChangeDetectorRef,
     private logger: NGXLogger
@@ -154,13 +159,24 @@ export class TreeComponent implements OnInit, OnDestroy, AfterViewInit {
         this.psDirectiveRef.update();
       }
     );
+    this.activateSubscription = this.activate$.subscribe(activate => {
+      if (activate) {
+        setTimeout(() => {
+          if (!!this.cvsvOrganization) {
+            this.cvsvOrganization.checkViewportSize();
+          }
+        }, 100);
+      }
+    });
   }
 
   ngOnDestroy(): void {
-    this.logger.debug('-----------------------TreeComponent ngOnDestroy');
     if (!!this.treeControlExpansionChangeSubscription) {
       this.treeControlExpansionChangeSubscription.unsubscribe();
     }
+    if (!!this.activateSubscription) {
+      this.activateSubscription.unsubscribe();
+    }
   }
 
   ngAfterViewInit(): void {
diff --git a/projects/ucap-webmessenger-ui/src/lib/directives/cdk-virtual-scroll-viewport-patch.directive.ts b/projects/ucap-webmessenger-ui/src/lib/directives/cdk-virtual-scroll-viewport-patch.directive.ts
index 849879a6..6ce2d95f 100644
--- a/projects/ucap-webmessenger-ui/src/lib/directives/cdk-virtual-scroll-viewport-patch.directive.ts
+++ b/projects/ucap-webmessenger-ui/src/lib/directives/cdk-virtual-scroll-viewport-patch.directive.ts
@@ -1,7 +1,15 @@
-import { Directive, OnInit, OnDestroy, Self, Inject } from '@angular/core';
+import {
+  Directive,
+  OnInit,
+  OnDestroy,
+  Self,
+  Inject,
+  ChangeDetectorRef
+} from '@angular/core';
 import { Subject, fromEvent } from 'rxjs';
 import { CdkVirtualScrollViewport } from '@angular/cdk/scrolling';
 import { debounceTime, takeUntil } from 'rxjs/operators';
+import { DOCUMENT } from '@angular/common';
 
 @Directive({
   // tslint:disable-next-line: directive-selector
@@ -14,13 +22,17 @@ export class CdkVirtualScrollViewportPatchDirective
   constructor(
     @Self()
     @Inject(CdkVirtualScrollViewport)
-    private readonly viewportComponent: CdkVirtualScrollViewport
+    private readonly viewportComponent: CdkVirtualScrollViewport,
+    @Inject(DOCUMENT)
+    private readonly document: Document
   ) {}
 
   ngOnInit() {
-    fromEvent(window, 'resize')
+    fromEvent(this.document.defaultView, 'resize')
       .pipe(debounceTime(10), takeUntil(this.destroySubject))
-      .subscribe(() => this.viewportComponent.checkViewportSize());
+      .subscribe(() => {
+        this.viewportComponent.checkViewportSize();
+      });
   }
 
   ngOnDestroy() {