diff --git a/server/gameserver/android.ai.cc b/server/gameserver/android.ai.cc
index ce6a220..9fcf947 100644
--- a/server/gameserver/android.ai.cc
+++ b/server/gameserver/android.ai.cc
@@ -706,6 +706,9 @@ Human* AndroidNewAI::GetTarget()
              if (a8::HasBitFlag(hum->status, HS_Disable)) {
                  return;
              }
+             if (hum->HasBuffEffect(kBET_InGrass)) {
+                 return;
+             }
              if (myself->team_id == hum->team_id) {
                  return;
              }
diff --git a/server/gameserver/constant.h b/server/gameserver/constant.h
index bac9e77..d7f9fd8 100755
--- a/server/gameserver/constant.h
+++ b/server/gameserver/constant.h
@@ -405,3 +405,7 @@ const int HUNLUAN_BUFFID = 6001;
 
 const int DRIVER_BUFFID = 6003;
 const int PASSENGER_BUFFID = 6004;
+
+const int GRASS_HIDE_BUFF_ID = 6005;
+const int WATER_BUFF_ID = 6006;
+const int ICE_BUFF_ID = 6007;
diff --git a/server/gameserver/human.cc b/server/gameserver/human.cc
index 86e5f87..9e97c9c 100644
--- a/server/gameserver/human.cc
+++ b/server/gameserver/human.cc
@@ -4335,30 +4335,169 @@ void Human::CheckSpecObject()
 
 void Human::OnEnterGrass()
 {
-
+    if (leave_grass_timer_) {
+        room->xtimer.DeleteTimer(leave_grass_timer_);
+        leave_grass_timer_ = nullptr;
+    }
+    if (hide_grass_timer_) {
+        room->xtimer.DeleteTimer(hide_grass_timer_);
+        hide_grass_timer_ = nullptr;
+    }
+    hide_grass_timer_ = room->xtimer.AddDeadLineTimerAndAttach
+        (MetaMgr::Instance()->grass_invisible_time * SERVER_FRAME_RATE,
+         a8::XParams()
+         .SetSender(this),
+         [] (const a8::XParams& param)
+         {
+             Human* hum = (Human*)param.sender.GetUserData();
+             MetaData::Buff* buff_meta = MetaMgr::Instance()->GetBuff(GRASS_HIDE_BUFF_ID);
+             if (buff_meta) {
+                 hum->AddBuff(hum, buff_meta, 1);
+             }
+         },
+         &xtimer_attacher.timer_list_,
+         [] (const a8::XParams& param)
+         {
+            Human* hum = (Human*)param.sender.GetUserData();
+            hum->hide_grass_timer_ = nullptr;
+         });
 }
 
 void Human::OnLeaveGrass()
 {
-
+    if (hide_grass_timer_) {
+        room->xtimer.DeleteTimer(hide_grass_timer_);
+        hide_grass_timer_ = nullptr;
+    }
+    if (leave_grass_timer_) {
+        room->xtimer.DeleteTimer(leave_grass_timer_);
+    }
+    leave_grass_timer_ = room->xtimer.AddDeadLineTimerAndAttach
+        (MetaMgr::Instance()->grass_show_time * SERVER_FRAME_RATE,
+         a8::XParams()
+         .SetSender(this),
+         [] (const a8::XParams& param)
+         {
+             Human* hum = (Human*)param.sender.GetUserData();
+             hum->leave_grass_timer_ = nullptr;
+             hum->RemoveBuffById(GRASS_HIDE_BUFF_ID);
+         },
+         &xtimer_attacher.timer_list_,
+         [] (const a8::XParams& param)
+         {
+             Human* hum = (Human*)param.sender.GetUserData();
+             hum->leave_grass_timer_ = nullptr;
+         });
 }
 
 void Human::OnEnterWater()
 {
-
+    if (leave_water_timer_) {
+        room->xtimer.DeleteTimer(leave_water_timer_);
+        leave_water_timer_ = nullptr;
+    }
+    if (hide_water_timer_) {
+        room->xtimer.DeleteTimer(hide_water_timer_);
+        hide_water_timer_ = nullptr;
+    }
+    hide_water_timer_ = room->xtimer.AddDeadLineTimerAndAttach
+        (MetaMgr::Instance()->water_invisible_time * SERVER_FRAME_RATE,
+         a8::XParams()
+         .SetSender(this),
+         [] (const a8::XParams& param)
+         {
+             Human* hum = (Human*)param.sender.GetUserData();
+             MetaData::Buff* buff_meta = MetaMgr::Instance()->GetBuff(WATER_BUFF_ID);
+             if (buff_meta) {
+                 hum->AddBuff(hum, buff_meta, 1);
+             }
+         },
+         &xtimer_attacher.timer_list_,
+         [] (const a8::XParams& param)
+         {
+            Human* hum = (Human*)param.sender.GetUserData();
+            hum->hide_water_timer_ = nullptr;
+         });
 }
 
 void Human::OnLeaveWater()
 {
-
+    if (hide_water_timer_) {
+        room->xtimer.DeleteTimer(hide_water_timer_);
+        hide_water_timer_ = nullptr;
+    }
+    if (leave_water_timer_) {
+        room->xtimer.DeleteTimer(leave_water_timer_);
+    }
+    leave_water_timer_ = room->xtimer.AddDeadLineTimerAndAttach
+        (MetaMgr::Instance()->water_show_time * SERVER_FRAME_RATE,
+         a8::XParams()
+         .SetSender(this),
+         [] (const a8::XParams& param)
+         {
+             Human* hum = (Human*)param.sender.GetUserData();
+             hum->RemoveBuffById(WATER_BUFF_ID);
+         },
+         &xtimer_attacher.timer_list_,
+         [] (const a8::XParams& param)
+         {
+             Human* hum = (Human*)param.sender.GetUserData();
+             hum->leave_water_timer_ = nullptr;
+         });
 }
 
 void Human::OnEnterIce()
 {
-
+    if (leave_ice_timer_) {
+        room->xtimer.DeleteTimer(leave_ice_timer_);
+        leave_ice_timer_ = nullptr;
+    }
+    if (hide_ice_timer_) {
+        room->xtimer.DeleteTimer(hide_ice_timer_);
+        hide_ice_timer_ = nullptr;
+    }
+    hide_ice_timer_ = room->xtimer.AddDeadLineTimerAndAttach
+        (MetaMgr::Instance()->ice_invisible_time * SERVER_FRAME_RATE,
+         a8::XParams()
+         .SetSender(this),
+         [] (const a8::XParams& param)
+         {
+             Human* hum = (Human*)param.sender.GetUserData();
+             MetaData::Buff* buff_meta = MetaMgr::Instance()->GetBuff(ICE_BUFF_ID);
+             if (buff_meta) {
+                 hum->AddBuff(hum, buff_meta, 1);
+             }
+         },
+         &xtimer_attacher.timer_list_,
+         [] (const a8::XParams& param)
+         {
+            Human* hum = (Human*)param.sender.GetUserData();
+            hum->hide_ice_timer_ = nullptr;
+         });
 }
 
 void Human::OnLeaveIce()
 {
-
+    if (hide_ice_timer_) {
+        room->xtimer.DeleteTimer(hide_ice_timer_);
+        hide_ice_timer_ = nullptr;
+    }
+    if (leave_ice_timer_) {
+        room->xtimer.DeleteTimer(leave_ice_timer_);
+    }
+    leave_ice_timer_ = room->xtimer.AddDeadLineTimerAndAttach
+        (MetaMgr::Instance()->ice_show_time * SERVER_FRAME_RATE,
+         a8::XParams()
+         .SetSender(this),
+         [] (const a8::XParams& param)
+         {
+             Human* hum = (Human*)param.sender.GetUserData();
+             hum->RemoveBuffById(ICE_BUFF_ID);
+         },
+         &xtimer_attacher.timer_list_,
+         [] (const a8::XParams& param)
+         {
+             Human* hum = (Human*)param.sender.GetUserData();
+             hum->leave_ice_timer_ = nullptr;
+         });
 }
diff --git a/server/gameserver/human.h b/server/gameserver/human.h
index e6452b3..79c278f 100644
--- a/server/gameserver/human.h
+++ b/server/gameserver/human.h
@@ -436,6 +436,13 @@ private:
     Entity* last_collision_door_ = nullptr;
     long long jump_frameno_ = 0;
 
+    xtimer_list* leave_grass_timer_ = nullptr;
+    xtimer_list* hide_grass_timer_ = nullptr;
+    xtimer_list* leave_water_timer_ = nullptr;
+    xtimer_list* hide_water_timer_ = nullptr;
+    xtimer_list* leave_ice_timer_ = nullptr;
+    xtimer_list* hide_ice_timer_ = nullptr;
+
     friend class FrameMaker;
     friend class FrameEvent;
 };
diff --git a/server/gameserver/metamgr.h b/server/gameserver/metamgr.h
index e3ffdb0..17b7195 100755
--- a/server/gameserver/metamgr.h
+++ b/server/gameserver/metamgr.h
@@ -124,6 +124,16 @@ class MetaMgr : public a8::Singleton<MetaMgr>
     int level1room_robot_autodie_distance = 0;
     std::string level1room_born_point;
 
+    float grass_invisible_time = 0.5;
+    float grass_show_time = 0.5f;
+    float grass_invisible_time2 = 2.0f;
+    float water_invisible_time = 0.5;
+    float water_show_time = 0.5f;
+    float water_invisible_time2 = 2.0f;
+    float ice_invisible_time = 0.5;
+    float ice_show_time = 0.5f;
+    float ice_invisible_time2 = 2.0f;
+
     #if 0
     int refresh_robot_min_num = 0;
     int refresh_robot_max_num = 0;