diff --git a/BE/src/chat/chat.service.ts b/BE/src/chat/chat.service.ts
index a0ffa6f..67e4803 100644
--- a/BE/src/chat/chat.service.ts
+++ b/BE/src/chat/chat.service.ts
@@ -40,7 +40,16 @@ export class ChatService {
     chat.chat_room = message.room_id;
     chat.is_read = is_read;
     chat.count = message.count;
-    await this.chatRepository.save(chat);
+    const lastChat = await this.chatRepository.save(chat);
+
+    await this.chatRoomRepository.update(
+      {
+        id: message.room_id,
+      },
+      {
+        last_chat_id: lastChat.id,
+      },
+    );
   }
 
   async createRoom(
@@ -79,24 +88,12 @@ export class ChatService {
   async findRoomList(userId: string) {
     const chatListInfo = { all_read: true, chat_list: [] };
 
-    const subquery = this.chatRepository
-      .createQueryBuilder('chat')
-      .select('chat.id', 'id')
-      .addSelect('chat.chat_room', 'chat_room')
-      .addSelect('chat.message', 'message')
-      .addSelect('chat.create_date', 'create_date')
-      .addSelect('chat.is_read', 'is_read')
-      .addSelect('chat.sender', 'sender')
-      .where(
-        'chat.id IN (SELECT MAX(chat.id) FROM chat GROUP BY chat.chat_room)',
-      );
-
     const rooms = await this.chatRoomRepository
       .createQueryBuilder('chat_room')
       .innerJoin(
-        '(' + subquery.getQuery() + ')',
+        'chat_room.lastChat',
         'chat_info',
-        'chat_room.id = chat_info.chat_room',
+        'chat_room.lastChat = chat_info.id',
       )
       .innerJoin(
         'chat_room.writerUser',
@@ -162,24 +159,12 @@ export class ChatService {
   }
 
   async unreadChat(userId: string) {
-    const subquery = this.chatRepository
-      .createQueryBuilder('chat')
-      .select('chat.id', 'id')
-      .addSelect('chat.chat_room', 'chat_room')
-      .addSelect('chat.message', 'message')
-      .addSelect('chat.create_date', 'create_date')
-      .addSelect('chat.is_read', 'is_read')
-      .addSelect('chat.sender', 'sender')
-      .where(
-        'chat.id IN (SELECT MAX(chat.id) FROM chat GROUP BY chat.chat_room)',
-      );
-
     const rooms = await this.chatRoomRepository
       .createQueryBuilder('chat_room')
       .innerJoin(
-        '(' + subquery.getQuery() + ')',
+        'chat_room.lastChat',
         'chat_info',
-        'chat_room.id = chat_info.chat_room',
+        'chat_room.lastChat = chat_info.id',
       )
       .innerJoin(
         'chat_room.writerUser',
diff --git a/BE/src/entities/chatRoom.entity.ts b/BE/src/entities/chatRoom.entity.ts
index 4a37ffe..f9bc493 100644
--- a/BE/src/entities/chatRoom.entity.ts
+++ b/BE/src/entities/chatRoom.entity.ts
@@ -8,6 +8,7 @@ import {
   ManyToOne,
   OneToMany,
   PrimaryGeneratedColumn,
+  OneToOne,
 } from 'typeorm';
 import { PostEntity } from './post.entity';
 import { ChatEntity } from './chat.entity';
@@ -42,6 +43,9 @@ export class ChatRoomEntity {
   @DeleteDateColumn()
   delete_date: Date;
 
+  @Column()
+  last_chat_id: number;
+
   @Column({ default: false })
   writer_left: boolean;
 
@@ -51,6 +55,10 @@ export class ChatRoomEntity {
   @OneToMany(() => ChatEntity, (chat) => chat.chatRoom)
   chats: ChatEntity[];
 
+  @OneToOne(() => ChatEntity, (chat) => chat.id)
+  @JoinColumn({ name: 'last_chat_id' })
+  lastChat: ChatEntity;
+
   @ManyToOne(() => PostEntity, (post) => post.id)
   @JoinColumn({ name: 'post_id' })
   post: PostEntity;