diff --git a/apps/client/src/network/SocketClient.ts b/apps/client/src/network/SocketClient.ts
index a14d709..11bdc85 100644
--- a/apps/client/src/network/SocketClient.ts
+++ b/apps/client/src/network/SocketClient.ts
@@ -1,13 +1,6 @@
 import { io, Socket } from "socket.io-client";
 import { SocketEvents } from "@repo/shared/src/protocol/events";
-
-// プレイヤーの基本情報を定義する型
-export type PlayerData = {
-  id: string;
-  x: number;
-  y: number;
-  color: string;
-};
+import type { PlayerData } from "@repo/shared/src/types/player";
 
 /**
  * サーバーとのWebSocket通信を管理するクライアントクラス
diff --git a/apps/server/src/network/SocketManager.ts b/apps/server/src/network/SocketManager.ts
index a32636d..10d4e38 100644
--- a/apps/server/src/network/SocketManager.ts
+++ b/apps/server/src/network/SocketManager.ts
@@ -4,6 +4,7 @@
 // shared側の型をインポート（※パスは実際の環境に合わせて修正してください）
 import { Room, RoomStatus } from "@repo/shared/src/types/room";
 import { SocketEvents } from "@repo/shared/src/protocol/events";
+import { GAME_CONFIG } from "@repo/shared/src/config/gameConfig";
 
 type RoomPlayer = Room["players"][0];
 
@@ -41,7 +42,7 @@
             ownerId: socket.id, // 最初に作った人がオーナー
             players: [],
             status: RoomStatus.WAITING,
-            maxPlayers: 4
+            maxPlayers: GAME_CONFIG.MAX_PLAYERS_PER_ROOM
           };
           this.rooms.set(roomId, room);
         }
diff --git a/packages/shared/src/config/gameConfig.ts b/packages/shared/src/config/gameConfig.ts
index 6ed6666..bd60d31 100644
--- a/packages/shared/src/config/gameConfig.ts
+++ b/packages/shared/src/config/gameConfig.ts
@@ -6,6 +6,9 @@
   // マップ設定
   MAP_WIDTH: 2000,
   MAP_HEIGHT: 2000,
+  
+  // ルーム設定
+  MAX_PLAYERS_PER_ROOM: 4,
 
   // プレイヤー設定
   PLAYER_RADIUS: 10,      // キャラの大きさ
diff --git a/packages/shared/src/types/player.ts b/packages/shared/src/types/player.ts
new file mode 100644
index 0000000..90b43b2
--- /dev/null
+++ b/packages/shared/src/types/player.ts
@@ -0,0 +1,7 @@
+// プレイヤーの基本情報を定義する共通型
+export interface PlayerData {
+  id: string;
+  x: number;
+  y: number;
+  color: string;
+}
\ No newline at end of file
diff --git a/packages/shared/src/types/room.ts b/packages/shared/src/types/room.ts
index 994fd39..8edade6 100644
--- a/packages/shared/src/types/room.ts
+++ b/packages/shared/src/types/room.ts
@@ -14,7 +14,7 @@
 } as const;
 export type RoomStatus = typeof RoomStatus[keyof typeof RoomStatus];
 
-export interface Player {
+export interface RoomMember {
   id: string;
   name: string;
   isOwner: boolean;
@@ -24,7 +24,7 @@
 export interface Room {
   roomId: string;
   ownerId: string;
-  players: Player[];
+  players: RoomMember[];
   status: RoomStatus;  // 👈 ここで上記の型を使用する
   maxPlayers: number;
 }