diff --git a/src/Collections/EcsGroup.cs b/src/Collections/EcsGroup.cs
index f56b442..9624a10 100644
--- a/src/Collections/EcsGroup.cs
+++ b/src/Collections/EcsGroup.cs
@@ -853,7 +853,25 @@ namespace DCFApixels.DragonECS
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public int Last() { return _dense[_count]; }
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        internal void OnWorldResize(int newSize) { Array.Resize(ref _sparse, newSize); }
+        internal void OnWorldResize_Internal(int newSize)
+        {
+            Array.Resize(ref _sparse, newSize);
+        }
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        internal void OnReleaseDelEntityBuffer_Internal(ReadOnlySpan<int> buffer)
+        {
+            if (_count <= 0)
+            {
+                return;
+            }
+            foreach (var entityID in buffer)
+            {
+                if (Has(entityID))
+                {
+                    Remove_Internal(entityID);
+                }
+            }
+        }
         public override string ToString()
         {
             return CollectionUtility.EntitiesToString(_dense.Skip(1).Take(_count), "group");
diff --git a/src/EcsWorld.cs b/src/EcsWorld.cs
index dc825ca..487844b 100644
--- a/src/EcsWorld.cs
+++ b/src/EcsWorld.cs
@@ -462,8 +462,7 @@ namespace DCFApixels.DragonECS
                 return;
             }
             unchecked { _version++; }
-            count = Math.Min(count, _delEntBufferCount);
-            count = Math.Max(count, 0);
+            count = Math.Max(0, Math.Min(count, _delEntBufferCount));
             _delEntBufferCount -= count;
             int slisedCount = count;
 
@@ -488,6 +487,17 @@ namespace DCFApixels.DragonECS
                     _pools[i].OnReleaseDelEntityBuffer(bufferSlised);
                 }
             }
+            for (int i = 0; i < _groups.Count; i++)
+            {
+                if (_groups[i].TryGetTarget(out EcsGroup group) && group.IsReleased)
+                {
+                    group.OnReleaseDelEntityBuffer_Internal(buffer);
+                }
+                else
+                {
+                    RemoveGroupAt(i--);
+                }
+            }
 
             _listeners.InvokeOnReleaseDelEntityBuffer(buffer);
             for (int i = 0; i < buffer.Length; i++)
@@ -525,25 +535,28 @@ namespace DCFApixels.DragonECS
             {
                 if (_groups[i].TryGetTarget(out EcsGroup group))
                 {
-                    group.OnWorldResize(newSize);
+                    group.OnWorldResize_Internal(newSize);
                 }
                 else
                 {
-                    int last = _groups.Count - 1;
-                    _groups[i--] = _groups[last];
-                    _groups.RemoveAt(last);
+                    RemoveGroupAt(i--);
                 }
             }
             foreach (var item in _pools)
             {
                 item.OnWorldResize(newSize);
             }
-
             _listeners.InvokeOnWorldResize(newSize);
         }
         #endregion
 
         #region Groups Pool
+        private void RemoveGroupAt(int index)
+        {
+            int last = _groups.Count - 1;
+            _groups[index] = _groups[last];
+            _groups.RemoveAt(last);
+        }
         internal void RegisterGroup(EcsGroup group)
         {
             _groups.Add(new WeakReference<EcsGroup>(group));