diff --git a/server/gameserver/building.cc b/server/gameserver/building.cc
index a885cbb..68eb46d 100644
--- a/server/gameserver/building.cc
+++ b/server/gameserver/building.cc
@@ -3,7 +3,6 @@
 #include "building.h"
 #include "collider.h"
 #include "metamgr.h"
-#include "room.h"
 #include "loot.h"
 #include "app.h"
 #include "typeconvert.h"
diff --git a/server/gameserver/bullet.cc b/server/gameserver/bullet.cc
index fdbb7d0..ee98eda 100644
--- a/server/gameserver/bullet.cc
+++ b/server/gameserver/bullet.cc
@@ -8,7 +8,7 @@
 #include "player.h"
 #include "app.h"
 
-Bullet::Bullet():Entity()
+Bullet::Bullet():RoomEntity()
 {
     entity_type = ET_Bullet;
     ++App::Instance()->perf.entity_num[ET_Bullet];
diff --git a/server/gameserver/bullet.h b/server/gameserver/bullet.h
index e5400b9..e81094d 100644
--- a/server/gameserver/bullet.h
+++ b/server/gameserver/bullet.h
@@ -1,6 +1,6 @@
 #pragma once
 
-#include "entity.h"
+#include "roomentity.h"
 
 namespace MetaData
 {
@@ -13,7 +13,7 @@ class Human;
 class Obstacle;
 class CircleCollider;
 class MovementComponent;
-class Bullet : public Entity
+class Bullet : public RoomEntity
 {
  public:
     int gun_lv = 0;
diff --git a/server/gameserver/entity.cc b/server/gameserver/entity.cc
index 5acd940..c5bd502 100644
--- a/server/gameserver/entity.cc
+++ b/server/gameserver/entity.cc
@@ -19,7 +19,9 @@ Entity::~Entity()
 
 void Entity::Initialize()
 {
+    #if 0
     xtimer_attacher.xtimer = &room->xtimer;
+    #endif
 }
 
 void Entity::GetAabbBox(AabbCollider& aabb_box)
diff --git a/server/gameserver/entity.h b/server/gameserver/entity.h
index 9edc002..ab88aae 100644
--- a/server/gameserver/entity.h
+++ b/server/gameserver/entity.h
@@ -24,7 +24,6 @@ class Entity
     Room* room = nullptr;
     int updated_times = 0;
     bool deleted = false;
-    a8::XTimerAttacher xtimer_attacher;
 
     bool is_permanent = false;
     MapService* permanent_map_service = nullptr;
diff --git a/server/gameserver/human.cc b/server/gameserver/human.cc
index f9c4d8e..0912cac 100644
--- a/server/gameserver/human.cc
+++ b/server/gameserver/human.cc
@@ -28,7 +28,7 @@
 const int kReviveTimeAdd = 12;
 const int kSkinNum = 4;
 
-Human::Human():Entity()
+Human::Human():RoomEntity()
 {
     default_weapon.weapon_idx = 0;
     default_weapon.weapon_id = 12101;
diff --git a/server/gameserver/human.h b/server/gameserver/human.h
index 97f580a..6920273 100644
--- a/server/gameserver/human.h
+++ b/server/gameserver/human.h
@@ -1,6 +1,6 @@
 #pragma once
 
-#include "entity.h"
+#include "roomentity.h"
 #include "cs_proto.pb.h"
 #include "GGListener.h"
 
@@ -26,7 +26,7 @@ class AabbCollider;
 class Obstacle;
 class Loot;
 class Buff;
-class Human : public Entity
+class Human : public RoomEntity
 {
  public:
     int socket_handle = 0;
@@ -45,6 +45,7 @@ class Human : public Entity
     MetaData::Dress* skin_jlf_meta = nullptr;
     MetaData::Equip* skin_tank_meta = nullptr;
     HumanAbility ability;
+    a8::XTimerAttacher xtimer_attacher;
 
     a8::Vec2 move_dir;
     a8::Vec2 attack_dir;
diff --git a/server/gameserver/loot.cc b/server/gameserver/loot.cc
index db1999f..f12aaa3 100644
--- a/server/gameserver/loot.cc
+++ b/server/gameserver/loot.cc
@@ -8,7 +8,7 @@
 #include "app.h"
 #include "typeconvert.h"
 
-Loot::Loot():Entity()
+Loot::Loot():RoomEntity()
 {
     entity_type = ET_Loot;
     ++App::Instance()->perf.entity_num[ET_Loot];
diff --git a/server/gameserver/loot.h b/server/gameserver/loot.h
index 48110e0..4548d4c 100644
--- a/server/gameserver/loot.h
+++ b/server/gameserver/loot.h
@@ -1,6 +1,6 @@
 #pragma once
 
-#include "entity.h"
+#include "roomentity.h"
 
 namespace MetaData
 {
@@ -10,7 +10,7 @@ namespace MetaData
 }
 
 class Human;
-class Loot : public Entity
+class Loot : public RoomEntity
 {
  public:
     MetaData::Equip* meta = nullptr;
diff --git a/server/gameserver/obstacle.cc b/server/gameserver/obstacle.cc
index be0eb50..41f3b5e 100644
--- a/server/gameserver/obstacle.cc
+++ b/server/gameserver/obstacle.cc
@@ -72,7 +72,7 @@ void Obstacle::RecalcSelfCollider()
                 }
                 self_collider_->pos = a8::Vec2();
                 self_collider_->rad = meta->i->height() / 2.0;
-                room->map_service.AddCollider(self_collider_);
+                permanent_map_service->AddCollider(self_collider_);
             }
             break;
         case 2:
@@ -84,7 +84,7 @@ void Obstacle::RecalcSelfCollider()
                 }
                 self_collider2_->_min = a8::Vec2(meta->i->width() / -2.0f, meta->i->height() / -2.0f);
                 self_collider2_->_max = a8::Vec2(meta->i->width() / 2.0f, meta->i->height() / 2.0f);
-                room->map_service.AddCollider(self_collider2_);
+                permanent_map_service->AddCollider(self_collider2_);
             }
             break;
         }
diff --git a/server/gameserver/room.cc b/server/gameserver/room.cc
index cf3d2d6..5b4b729 100644
--- a/server/gameserver/room.cc
+++ b/server/gameserver/room.cc
@@ -445,7 +445,7 @@ void Room::CreateBullet(Human* hum, Weapon* weapon,
     }
 }
 
-void Room::RemoveObjectLater(Entity* entity)
+void Room::RemoveObjectLater(RoomEntity* entity)
 {
     auto remove_func = [] (const a8::XParams& param)
                        {
@@ -1180,11 +1180,11 @@ Obstacle* Room::InternalCreateObstacle(int id, float x, float y,
     return nullptr;
 }
 
-void Room::AddObjectLater(Entity* entity)
+void Room::AddObjectLater(RoomEntity* entity)
 {
     auto add_func = [] (const a8::XParams& param)
                        {
-                           Entity* entity = (Entity*)param.sender.GetUserData();
+                           RoomEntity* entity = (RoomEntity*)param.sender.GetUserData();
                            if (entity->entity_type == ET_Bullet) {
                                entity->room->moveable_hash_[entity->entity_uniid] = entity;
                            }
diff --git a/server/gameserver/room.h b/server/gameserver/room.h
index 34112fc..1568af8 100644
--- a/server/gameserver/room.h
+++ b/server/gameserver/room.h
@@ -25,6 +25,7 @@ namespace metatable
 struct timer_list;
 struct xtimer_list;
 class Entity;
+class RoomEntity;
 class Obstacle;
 class Bullet;
 class Human;
@@ -72,7 +73,7 @@ public:
     void AddPlayer(Player* hum);
     Human* FindEnemy(Human* hum);
 
-    void RemoveObjectLater(Entity* entity);
+    void RemoveObjectLater(RoomEntity* entity);
 
     void FillSMJoinedNotify(Player* self_hum, cs::SMJoinedNotify& msg);
 
@@ -129,7 +130,7 @@ private:
     Obstacle* CreateObstacle(int id, float x, float y);
     Obstacle* InternalCreateObstacle(int id, float x, float y,
                                      std::function<void (Obstacle*)> on_precreate);
-    void AddObjectLater(Entity* entity);
+    void AddObjectLater(RoomEntity* entity);
     void OnGameOver();
     void RandRemoveAndroid();
     void NotifyWxVoip();
diff --git a/server/gameserver/roomentity.cc b/server/gameserver/roomentity.cc
new file mode 100644
index 0000000..e69de29
diff --git a/server/gameserver/roomentity.h b/server/gameserver/roomentity.h
new file mode 100644
index 0000000..efc6969
--- /dev/null
+++ b/server/gameserver/roomentity.h
@@ -0,0 +1,10 @@
+#pragma once
+
+#include "entity.h"
+
+class RoomEntity : public Entity
+{
+ public:
+    a8::XTimerAttacher xtimer_attacher;
+
+};