diff --git a/server/gameserver/hero_agent.cc b/server/gameserver/hero_agent.cc
index c9c9f542..8929e3f0 100644
--- a/server/gameserver/hero_agent.cc
+++ b/server/gameserver/hero_agent.cc
@@ -999,30 +999,47 @@ bool HeroAgent::TargetInRange(float range)
 
 float HeroAgent::GetNewAttackerHPRate()
 {
-
+    return owner_->GetLastAttacker().Get()->GetHP() /
+        std::max(1.0f, owner_->GetLastAttacker().Get()->GetMaxHP());
 }
 
 bool HeroAgent::GetNewAttackerInRange(float range)
 {
-
+    if (!HasNewAttacker()) {
+        return false;
+    }
+    return Collision::InSquare
+        (owner_->GetLastAttacker().Get()->GetPos().ToGlmVec3(),
+         owner_->GetPos().ToGlmVec3(),
+         range);
 }
 
 int HeroAgent::GetNewAttackerPassTime()
 {
-
+    return (owner_->room->GetFrameNo() - owner_->GetLastBeAttackFrameNo()) * FRAME_RATE_MS;
 }
 
 bool HeroAgent::HasNewAttacker()
 {
-
+    if (!current_target_agent->IsValid()) {
+        return false;
+    }
+    if (!owner_->GetLastAttacker().Get()) {
+        return false;
+    }
+    return current_target_agent->GetUniId() != owner_->GetLastAttacker().Get()->GetUniId() &&
+        owner_->GetLastAttacker().Get()->revive_count == owner_->GetLastAttackerReviveTimes();
 }
 
 bool HeroAgent::NewAttackerIsHuman()
 {
-
+    return owner_->GetLastAttacker().Get()->IsHuman();
 }
 
 bool HeroAgent::SwitchToNewAttacker()
 {
+    if (HasNewAttacker()) {
 
+    }
+    return true;
 }