diff --git a/src/main/java/com/saiko/bidmarket/chat/controller/dto/ChatRoomSelectResponse.java b/src/main/java/com/saiko/bidmarket/chat/controller/dto/ChatRoomSelectResponse.java
index e17dc3be..976873ef 100644
--- a/src/main/java/com/saiko/bidmarket/chat/controller/dto/ChatRoomSelectResponse.java
+++ b/src/main/java/com/saiko/bidmarket/chat/controller/dto/ChatRoomSelectResponse.java
@@ -44,8 +44,10 @@ public class ChatRoomSelectResponse {
   @Builder(access = PRIVATE)
   @RequiredArgsConstructor(access = PRIVATE)
   private static class ProductInfo {
+
     @Positive
     private final long productId;
+
     @NotBlank
     private final String thumbnailImg;
   }
@@ -55,8 +57,10 @@ private static class ProductInfo {
   @Builder(access = PRIVATE)
   @RequiredArgsConstructor(access = PRIVATE)
   private static class OpponentUserInfo {
-    @Positive
-    private final long userId;
+
+    @NotBlank
+    private final String username;
+
     @NotBlank
     private final String profileImg;
   }
@@ -76,7 +80,7 @@ public static ChatRoomSelectResponse of(
                                          .build();
 
     OpponentUserInfo opponentUserInfo = OpponentUserInfo.builder()
-                                                        .userId(opponent.getId())
+                                                        .username(opponent.getUsername())
                                                         .profileImg(opponent.getProfileImage())
                                                         .build();
 
diff --git a/src/test/java/com/saiko/bidmarket/chat/controller/ChatRoomApiControllerTest.java b/src/test/java/com/saiko/bidmarket/chat/controller/ChatRoomApiControllerTest.java
index 21465e93..d61529d7 100644
--- a/src/test/java/com/saiko/bidmarket/chat/controller/ChatRoomApiControllerTest.java
+++ b/src/test/java/com/saiko/bidmarket/chat/controller/ChatRoomApiControllerTest.java
@@ -100,8 +100,8 @@ void ItResponseChatRoomList() throws Exception {
                                         .type(JsonFieldType.NUMBER).description("상품 번호"),
                                     fieldWithPath("[].productInfo.thumbnailImg")
                                         .type(JsonFieldType.STRING).description("상품 이미지"),
-                                    fieldWithPath("[].opponentUserInfo.userId")
-                                        .type(JsonFieldType.NUMBER).description("상대방 유저 아이디"),
+                                    fieldWithPath("[].opponentUserInfo.username")
+                                        .type(JsonFieldType.STRING).description("상대방 유저명"),
                                     fieldWithPath("[].opponentUserInfo.profileImg")
                                         .type(JsonFieldType.STRING).description("상대방 유저 프로필"),
                                     fieldWithPath("[].lastMessage")