diff --git a/locals/Log.csv b/locals/Log.csv
index 1d732ec..35fb472 100644
--- a/locals/Log.csv
+++ b/locals/Log.csv
@@ -57,7 +57,6 @@ log_backpack_not_allowed,不允许添加到背包。,Not allowed to add to backp
 log_item_is_null,物品为空。,Item is null.,アイテムが空です。
 log_item_id_not_same,物品ID不同。,Item ID is different.,アイテムIDが異なります。
 log_max_quantity_exceeded,超过最大数量。,Exceeded maximum quantity.,最大数量を超えました。
-log_item_slot_is_selected_and_not_allowed,已选择物品槽，不允许添加。,"Item slot is selected, not allowed to add.",アイテムスロットが選択されており、追加は許可されていません。
 log_patrol_enemy_detected,检测到敌人。,Enemy detected.,敵を検出しました。
 log_attacker_or_target_is_null,攻击者或目标为空。,Attacker or target is null.,攻撃者またはターゲットが空です。
 log_in_the_same_camp,在同一阵营。,In the same camp.,同じ陣営です。
diff --git a/scripts/Config.cs b/scripts/Config.cs
index 0c7a679..b271ac2 100644
--- a/scripts/Config.cs
+++ b/scripts/Config.cs
@@ -210,6 +210,29 @@ public static class Config
         /// </summary>
         public const string TimeInterval = "TimeInterval";
     }
+    
+    /// <summary>
+    /// <para>Item data changes the event type</para>
+    /// <para>物品数据改变事件类型</para>
+    /// </summary>
+    public enum ItemDataChangeEventType
+    {
+        /// <summary>
+        /// <para>add</para>
+        /// <para>添加</para>
+        /// </summary>
+        Add,
+        /// <summary>
+        /// <para>Quantity Added</para>
+        /// <para>物品数量增加</para>
+        /// </summary>
+        QuantityAdded,
+        /// <summary>
+        /// <para>remove</para>
+        /// <para>移除</para>
+        /// </summary>
+        Remove
+    }
 
     public enum OsEnum
     {
diff --git a/scripts/inventory/IItemContainer.cs b/scripts/inventory/IItemContainer.cs
index 6206b60..ab1d22f 100644
--- a/scripts/inventory/IItemContainer.cs
+++ b/scripts/inventory/IItemContainer.cs
@@ -8,10 +8,6 @@ namespace ColdMint.scripts.inventory;
 /// <para>item container</para>
 /// <para>物品容器</para>
 /// </summary>
-/// <remarks>
-///<para>Item containers can store items. Things like backpacks and Hotbars are containers with visual pages.</para>
-///<para>物品容器可以储存物品。像背包和hotbar是具有可视化页面的容器。</para>
-/// </remarks>
 public interface IItemContainer : IEnumerable<IItem>
 {
     /// <summary>
@@ -20,6 +16,12 @@ public interface IItemContainer : IEnumerable<IItem>
     /// </summary>
     Action<SelectedItemChangeEvent>? SelectedItemChangeEvent { get; set; }
 
+    /// <summary>
+    /// <para>This event is triggered when the item's data changes, such as the number increases, decreases, or new items are added to the container</para>
+    /// <para>当物品的数据发生改变时，例如数量增加，减少，或者新物品被添加到容器内触发此事件</para>
+    /// </summary>
+    Action<ItemDataChangeEvent>? ItemDataChangeEvent { get; set; }
+
     /// <summary>
     /// <para>Can the specified item be added to the container?</para>
     /// <para>指定的物品是否可添加到容器内？</para>
diff --git a/scripts/inventory/ItemContainerDisplayTemplate.cs b/scripts/inventory/ItemContainerDisplayTemplate.cs
index 0799215..73e7cac 100644
--- a/scripts/inventory/ItemContainerDisplayTemplate.cs
+++ b/scripts/inventory/ItemContainerDisplayTemplate.cs
@@ -1,5 +1,6 @@
 using System.Collections;
 using System.Collections.Generic;
+using System.Threading.Tasks;
 using ColdMint.scripts.map.events;
 
 namespace ColdMint.scripts.inventory;
@@ -19,10 +20,12 @@ public abstract class ItemContainerDisplayTemplate : IItemContainerDisplay
         if (_itemContainer != null)
         {
             _itemContainer.SelectedItemChangeEvent -= OnSelectedItemChangeEvent;
+            _itemContainer.ItemDataChangeEvent -= OnItemDataChangeEvent;
         }
 
         _itemContainer = itemContainer;
         _itemContainer.SelectedItemChangeEvent += OnSelectedItemChangeEvent;
+        _itemContainer.ItemDataChangeEvent += OnItemDataChangeEvent;
         var totalCapacity = itemContainer.GetTotalCapacity();
         var currentCapacity = ItemDisplayList.Count;
         var capacityDifference = totalCapacity - currentCapacity;
@@ -53,6 +56,17 @@ public abstract class ItemContainerDisplayTemplate : IItemContainerDisplay
         UpdateData(itemContainer, adjustedEndIndex);
     }
 
+    private void OnItemDataChangeEvent(ItemDataChangeEvent itemDataChangeEvent)
+    {
+        if (_itemContainer == null)
+        {
+            return;
+        }
+
+        var usedCapacity = _itemContainer.GetUsedCapacity();
+        UpdateDataForSingleLocation(_itemContainer, itemDataChangeEvent.NewIndex, usedCapacity);
+    }
+
     private void OnSelectedItemChangeEvent(SelectedItemChangeEvent selectedItemChangeEvent)
     {
         if (_itemContainer == null)
diff --git a/scripts/inventory/ItemSlotNode.cs b/scripts/inventory/ItemSlotNode.cs
index c8507da..7ef5566 100644
--- a/scripts/inventory/ItemSlotNode.cs
+++ b/scripts/inventory/ItemSlotNode.cs
@@ -1,6 +1,4 @@
-using System;
 using ColdMint.scripts.debug;
-using ColdMint.scripts.pickable;
 using ColdMint.scripts.utils;
 using Godot;
 
@@ -16,7 +14,6 @@ public partial class ItemSlotNode : MarginContainer, IItemDisplay
     private TextureRect? _iconTextureRect;
     private Label? _quantityLabel;
     private Control? _control;
-    private bool _isSelect;
     private Texture2D? _backgroundTexture;
     private Texture2D? _backgroundTextureWhenSelect;
     private IItem? _item;
@@ -31,12 +28,11 @@ public partial class ItemSlotNode : MarginContainer, IItemDisplay
         _quantityLabel = GetNode<Label>("Control/QuantityLabel");
         _control = GetNode<Control>("Control");
         _quantityLabel.Hide();
-        UpdateBackground(_isSelect);
     }
 
     public override Variant _GetDragData(Vector2 atPosition)
     {
-        if (_isSelect || _iconTextureRect == null)
+        if (_iconTextureRect == null)
         {
             return new Variant();
         }
@@ -51,14 +47,6 @@ public partial class ItemSlotNode : MarginContainer, IItemDisplay
 
     public override bool _CanDropData(Vector2 atPosition, Variant data)
     {
-        if (_isSelect)
-        {
-            //Do not place items in the selected item slot, even if the item slot is empty.
-            //禁止在已选中的物品槽内放置物品，即使物品槽是空的。
-            LogCat.Log("item_slot_is_selected_and_not_allowed");
-            return false;
-        }
-
         //If the preplaced slot does not have an icon, the preplaced slot is not allowed.
         //如果预放置的槽位没有图标，那么不允许放置。
         if (_iconTextureRect == null)
@@ -129,7 +117,6 @@ public partial class ItemSlotNode : MarginContainer, IItemDisplay
     }
 
 
-
     public override void _DropData(Vector2 atPosition, Variant data)
     {
         if (_iconTextureRect == null)
@@ -188,15 +175,6 @@ public partial class ItemSlotNode : MarginContainer, IItemDisplay
     /// </summary>
     public bool BackpackAllowed { get; set; }
 
-    public bool IsSelect
-    {
-        get => _isSelect;
-        set
-        {
-            UpdateBackground(value);
-            _isSelect = value;
-        }
-    }
 
     private void UpdateBackground(bool isSelect)
     {
@@ -330,7 +308,12 @@ public partial class ItemSlotNode : MarginContainer, IItemDisplay
 
     public void Update(IItem? item)
     {
-        UpdateAllDisplay();
+        if (item is not PlaceholderItem)
+        {
+            _item = item;
+            UpdateAllDisplay();
+        }
+        UpdateBackground(item is { IsSelect: true });
     }
 
     public void ShowSelf()
diff --git a/scripts/inventory/PlaceholderItem.cs b/scripts/inventory/PlaceholderItem.cs
new file mode 100644
index 0000000..01ec472
--- /dev/null
+++ b/scripts/inventory/PlaceholderItem.cs
@@ -0,0 +1,32 @@
+using Godot;
+
+namespace ColdMint.scripts.inventory;
+
+/// <summary>
+/// <para>A blank item used to occupy a space in the display. The IsSelect property is set to true so that the item display always appears selected when drawn.</para>
+/// <para>物品容器显示器内用于占位的空白物品。IsSelect属性设置为true，使得物品显示器绘制时总是显示为选中状态。</para>
+/// </summary>
+public class PlaceholderItem : IItem
+{
+    public string Id { get; set; }
+    public Texture2D Icon { get; }
+    public string Name { get; }
+    public string? Description { get; } = null;
+    public int Quantity { get; set; } = 1;
+    public int MaxQuantity { get; } = 1;
+    public bool IsSelect { get; set; } = true;
+
+    public int MergeableItemCount(IItem other, int unallocatedQuantity)
+    {
+        return 0;
+    }
+
+    public IItem? CreateItem(int number)
+    {
+        return null;
+    }
+
+    public void Use(Node2D? owner, Vector2 targetGlobalPosition)
+    {
+    }
+}
\ No newline at end of file
diff --git a/scripts/inventory/UniversalItemContainer.cs b/scripts/inventory/UniversalItemContainer.cs
index fc1a2cb..254794e 100644
--- a/scripts/inventory/UniversalItemContainer.cs
+++ b/scripts/inventory/UniversalItemContainer.cs
@@ -37,6 +37,7 @@ public class UniversalItemContainer(int totalCapacity) : IItemContainer
     }
 
     public Action<SelectedItemChangeEvent>? SelectedItemChangeEvent { get; set; }
+    public Action<ItemDataChangeEvent>? ItemDataChangeEvent { get; set; }
 
     public bool CanAddItem(IItem item)
     {
@@ -75,6 +76,7 @@ public class UniversalItemContainer(int totalCapacity) : IItemContainer
         return unallocatedQuantity < 1;
     }
 
+
     public int AddItem(IItem item)
     {
         if (item.MaxQuantity == 1)
@@ -87,12 +89,19 @@ public class UniversalItemContainer(int totalCapacity) : IItemContainer
             }
 
             _itemList.Add(item);
+            ItemDataChangeEvent?.Invoke(new ItemDataChangeEvent
+            {
+                NewItem = item,
+                NewIndex = _itemList.Count - 1,
+                Type = Config.ItemDataChangeEventType.QuantityAdded
+            });
             return item.Quantity;
         }
 
         //There can be more than one item, try to share equally.
         //物品可有多个，尝试均摊。
         var originalQuantity = item.Quantity;
+        var index = 0;
         foreach (var unitItem in _itemList)
         {
             var number = unitItem.MergeableItemCount(item, item.Quantity);
@@ -103,19 +112,20 @@ public class UniversalItemContainer(int totalCapacity) : IItemContainer
 
             item.Quantity -= number;
             unitItem.Quantity += number;
+            ItemDataChangeEvent?.Invoke(new ItemDataChangeEvent
+            {
+                NewItem = unitItem,
+                NewIndex = index,
+                Type = Config.ItemDataChangeEventType.QuantityAdded
+            });
             if (item.Quantity < 1)
             {
                 //New items are fully shared.
                 //新物品完全被均摊。
                 return originalQuantity;
             }
-        }
 
-        if (item.Quantity < 1)
-        {
-            //After traversing to the last item, the new item is fully shared.
-            //在遍历到最后的物品，新物品完全被均摊。
-            return originalQuantity;
+            index++;
         }
 
         //New items have some left over.
@@ -130,6 +140,12 @@ public class UniversalItemContainer(int totalCapacity) : IItemContainer
         //Add the rest to the container.
         //添加剩余到容器内。
         _itemList.Add(item);
+        ItemDataChangeEvent?.Invoke(new ItemDataChangeEvent
+        {
+            NewItem = item,
+            NewIndex = _itemList.Count - 1,
+            Type = Config.ItemDataChangeEventType.Add
+        });
         return originalQuantity;
     }
 
diff --git a/scripts/map/events/ItemDataChangeEvent.cs b/scripts/map/events/ItemDataChangeEvent.cs
new file mode 100644
index 0000000..92b549b
--- /dev/null
+++ b/scripts/map/events/ItemDataChangeEvent.cs
@@ -0,0 +1,16 @@
+using ColdMint.scripts.inventory;
+
+namespace ColdMint.scripts.map.events;
+
+/// <summary>
+/// <para>Item Data Change Event</para>
+/// <para>项目数据改变事件</para>
+/// </summary>
+public class ItemDataChangeEvent
+{
+    public Config.ItemDataChangeEventType Type { get; set; }
+    public int OldIndex { get; set; }
+    public int NewIndex { get; set; }
+    public IItem? NewItem { get; set; }
+    public IItem? OldItem { get; set; }
+}
\ No newline at end of file
diff --git a/scripts/pickable/PickAbleTemplate.cs b/scripts/pickable/PickAbleTemplate.cs
index ed14771..83b61e4 100644
--- a/scripts/pickable/PickAbleTemplate.cs
+++ b/scripts/pickable/PickAbleTemplate.cs
@@ -76,11 +76,11 @@ public partial class PickAbleTemplate : RigidBody2D, IItem
     /// </summary>
     public bool Picked { get; set; }
 
-    public int MaxQuantity { get; set; }
+    public int MaxQuantity { get; set; } = 1;
     public bool IsSelect { get; set; }
 
     private Label? _tipLabel;
-    
+
     public IItem? CreateItem(int number)
     {
         if (number == 0)