diff --git a/internal/bossraid/handler.go b/internal/bossraid/handler.go
index 3c62670..8e20324 100644
--- a/internal/bossraid/handler.go
+++ b/internal/bossraid/handler.go
@@ -207,10 +207,18 @@ func (h *Handler) ValidateEntryToken(c *fiber.Ctx) error {
 		return apperror.Unauthorized(err.Error())
 	}
 
+	// 방 정보에서 파티 인원 수 조회
+	expectedPlayers := 0
+	room, roomErr := h.svc.GetRoom(sessionName)
+	if roomErr == nil && room != nil {
+		expectedPlayers = room.MaxPlayers
+	}
+
 	return c.JSON(fiber.Map{
-		"valid":       true,
-		"username":    username,
-		"sessionName": sessionName,
+		"valid":           true,
+		"username":        username,
+		"sessionName":     sessionName,
+		"expectedPlayers": expectedPlayers,
 	})
 }
 
diff --git a/internal/bossraid/service.go b/internal/bossraid/service.go
index 5d0e56b..5dbe579 100644
--- a/internal/bossraid/service.go
+++ b/internal/bossraid/service.go
@@ -110,7 +110,7 @@ func (s *Service) RequestEntry(usernames []string, bossID int) (*BossRoom, error
 			SessionName: slot.SessionName,
 			BossID:      bossID,
 			Status:      StatusWaiting,
-			MaxPlayers:  defaultMaxPlayers,
+			MaxPlayers:  len(usernames),
 			Players:     string(playersJSON),
 		}
 		if err := txRepo.Create(room); err != nil {