diff --git a/Assets/PerfectWorld/Scripts/Managers/EC_InventoryUI.cs b/Assets/PerfectWorld/Scripts/Managers/EC_InventoryUI.cs
index 817318d79f..83b2d9e1c9 100644
--- a/Assets/PerfectWorld/Scripts/Managers/EC_InventoryUI.cs
+++ b/Assets/PerfectWorld/Scripts/Managers/EC_InventoryUI.cs
@@ -58,6 +58,9 @@ namespace BrewMonster.Scripts.Managers
         [Header("Stack combine — merge into another stack (C++ inventory drag-merge, assign in Inspector)")]
         [SerializeField] private Button combineStackButton;
 
+        [Header("Sort / arrange pack (C++ DlgInventory arrange)")]
+        [SerializeField] private Button sortInventoryButton;
+
         private int _splitAmount = 1;
         private int _splitMaxAmount = 1;
 
@@ -137,6 +140,7 @@ namespace BrewMonster.Scripts.Managers
             WireBagTabButtons();
             WireSplitUI();
             WireCombineUI();
+            WireSortInventoryUI();
 
             //if (currentDragImage == null)
             //{
@@ -228,6 +232,60 @@ namespace BrewMonster.Scripts.Managers
             }
         }
 
+        private void WireSortInventoryUI()
+        {
+            ResolveSortInventoryButton();
+            if (sortInventoryButton != null)
+            {
+                sortInventoryButton.onClick.RemoveAllListeners();
+                sortInventoryButton.onClick.AddListener(OnSortInventoryClicked);
+            }
+        }
+
+        private void ResolveSortInventoryButton()
+        {
+            if (sortInventoryButton != null)
+                return;
+
+            var buttons = GetComponentsInChildren<Button>(true);
+            for (int i = 0; i < buttons.Length; i++)
+            {
+                var btn = buttons[i];
+                if (btn == null)
+                    continue;
+                string n = btn.name.ToLowerInvariant();
+                if (n.Contains("arrange") || n.Contains("sort") || n == "btn_arrange")
+                {
+                    sortInventoryButton = btn;
+                    break;
+                }
+            }
+        }
+
+        /// <summary>Arrange main inventory (IVTRTYPE_PACK). C++ CDlgInventory::OnCommand_arrange.</summary>
+        public void OnSortInventoryClicked()
+        {
+            if (_bagTab != InventoryBagTab.Item)
+            {
+                Debug.LogWarning("[InventoryUI] Sort pack: switch to Item tab first");
+                return;
+            }
+
+            var host = CECGameRun.Instance?.GetHostPlayer();
+            if (host == null)
+                return;
+
+            int cool = host.GetCoolTime((int)CoolTimeIndex.GP_CT_MULTI_EXCHANGE_ITEM, out _);
+            if (cool > 0)
+            {
+                EC_Game.GetGameRun()?.AddFixedMessage((int)FixedMsg.FIXMSG_CMD_INCOOLTIME);
+                return;
+            }
+
+            host.SortPack(InventoryConst.IVTRTYPE_PACK);
+            RefreshAll();
+        }
+
         private void ShowSplitPanel(bool show)
         {
             if (splitPanelRoot != null)
diff --git a/Assets/PerfectWorld/Scripts/Network/CSNetwork/C2SCommand/C2SCommandFactory.cs b/Assets/PerfectWorld/Scripts/Network/CSNetwork/C2SCommand/C2SCommandFactory.cs
index 0d3f910666..859bcb5515 100644
--- a/Assets/PerfectWorld/Scripts/Network/CSNetwork/C2SCommand/C2SCommandFactory.cs
+++ b/Assets/PerfectWorld/Scripts/Network/CSNetwork/C2SCommand/C2SCommandFactory.cs
@@ -439,6 +439,25 @@ namespace CSNetwork.C2SCommand
             return SerializeCommand(CommandID.MOVE_IVTR_ITEM, cmd);
         }
 
+        /// <summary>C++ c2s_SendCmdMultiExchangeItem — pack arrange / sort (variable-length operation list).</summary>
+        public static Octets CreateMultiExchangeItem(byte location, int pairCount, int[] indexPairs)
+        {
+            if (pairCount < 1 || indexPairs == null || indexPairs.Length < pairCount * 2)
+                return null;
+
+            var octets = new Octets();
+            WriteBasicValue(octets, (ushort)CommandID.MULTI_EXCHANGE_ITEM);
+            WriteBasicValue(octets, location);
+            WriteBasicValue(octets, (byte)pairCount);
+            for (int i = 0; i < pairCount; i++)
+            {
+                WriteBasicValue(octets, (byte)indexPairs[i * 2]);
+                WriteBasicValue(octets, (byte)indexPairs[i * 2 + 1]);
+            }
+
+            return octets;
+        }
+
         public static Octets CreatePickupItem(int idItem, int tid)
         {
             var cmd = new CMD_Pickup
diff --git a/Assets/PerfectWorld/Scripts/Network/CSNetwork/GameSession.cs b/Assets/PerfectWorld/Scripts/Network/CSNetwork/GameSession.cs
index 8de0c8bf4f..907e6ed19d 100644
--- a/Assets/PerfectWorld/Scripts/Network/CSNetwork/GameSession.cs
+++ b/Assets/PerfectWorld/Scripts/Network/CSNetwork/GameSession.cs
@@ -471,6 +471,16 @@ namespace CSNetwork
             SendProtocol(gamedatasendRequest);
         }
 
+        public void RequestMultiExchangeItem(byte location, int pairCount, int[] indexPairs)
+        {
+            var data = C2SCommandFactory.CreateMultiExchangeItem(location, pairCount, indexPairs);
+            if (data == null)
+                return;
+            var gamedatasendRequest = new gamedatasend();
+            gamedatasendRequest.Data = data;
+            SendProtocol(gamedatasendRequest);
+        }
+
         public void RequestPickupItem(int idItem, int tid)
         {
             gamedatasend gamedatasendRequest = new gamedatasend();
diff --git a/Assets/PerfectWorld/Scripts/Network/UnityGameSession.cs b/Assets/PerfectWorld/Scripts/Network/UnityGameSession.cs
index 7703cb0417..2551c38c7b 100644
--- a/Assets/PerfectWorld/Scripts/Network/UnityGameSession.cs
+++ b/Assets/PerfectWorld/Scripts/Network/UnityGameSession.cs
@@ -497,6 +497,12 @@ namespace BrewMonster.Network
         {
             Instance._gameSession.RequestMoveIvtrItem(src, dest, count);
         }
+
+        public static void RequestMultiExchangeItem(byte location, int pairCount, int[] indexPairs)
+        {
+            Instance._gameSession.RequestMultiExchangeItem(location, pairCount, indexPairs);
+        }
+
         public static void LoadConfigData()
         {
             Instance._gameSession.LoadConfigData();
diff --git a/Assets/Prefabs/UI/InventoryUI.prefab b/Assets/Prefabs/UI/InventoryUI.prefab
index dbea27ee03..ab58aeb70a 100644
--- a/Assets/Prefabs/UI/InventoryUI.prefab
+++ b/Assets/Prefabs/UI/InventoryUI.prefab
@@ -6807,13 +6807,14 @@ GameObject:
   - component: {fileID: 7902430374187284626}
   - component: {fileID: 2646092870800509053}
   - component: {fileID: 8343020880054062986}
+  - component: {fileID: 4947710734819332199}
   m_Layer: 5
   m_Name: sap_xep
   m_TagString: Untagged
   m_Icon: {fileID: 0}
   m_NavMeshLayer: 0
   m_StaticEditorFlags: 0
-  m_IsActive: 0
+  m_IsActive: 1
 --- !u!224 &7902430374187284626
 RectTransform:
   m_ObjectHideFlags: 0
@@ -6828,9 +6829,9 @@ RectTransform:
   m_Children: []
   m_Father: {fileID: 5322092470266254149}
   m_LocalEulerAnglesHint: {x: 0, y: 0, z: 0}
-  m_AnchorMin: {x: 0, y: 1}
-  m_AnchorMax: {x: 0, y: 1}
-  m_AnchoredPosition: {x: 37.5748, y: -45.8533}
+  m_AnchorMin: {x: 0, y: 0}
+  m_AnchorMax: {x: 0, y: 0}
+  m_AnchoredPosition: {x: 0, y: 0}
   m_SizeDelta: {x: 75.1496, y: 91.7066}
   m_Pivot: {x: 0.5, y: 0.5}
 --- !u!222 &2646092870800509053
@@ -6848,7 +6849,7 @@ MonoBehaviour:
   m_PrefabInstance: {fileID: 0}
   m_PrefabAsset: {fileID: 0}
   m_GameObject: {fileID: 2805221609055900627}
-  m_Enabled: 0
+  m_Enabled: 1
   m_EditorHideFlags: 0
   m_Script: {fileID: 11500000, guid: fe87c0e1cc204ed48ad3b37840f39efc, type: 3}
   m_Name: 
@@ -6871,6 +6872,50 @@ MonoBehaviour:
   m_FillOrigin: 0
   m_UseSpriteMesh: 0
   m_PixelsPerUnitMultiplier: 1
+--- !u!114 &4947710734819332199
+MonoBehaviour:
+  m_ObjectHideFlags: 0
+  m_CorrespondingSourceObject: {fileID: 0}
+  m_PrefabInstance: {fileID: 0}
+  m_PrefabAsset: {fileID: 0}
+  m_GameObject: {fileID: 2805221609055900627}
+  m_Enabled: 1
+  m_EditorHideFlags: 0
+  m_Script: {fileID: 11500000, guid: 4e29b1a8efbd4b44bb3f3716e73f07ff, type: 3}
+  m_Name: 
+  m_EditorClassIdentifier: 
+  m_Navigation:
+    m_Mode: 3
+    m_WrapAround: 0
+    m_SelectOnUp: {fileID: 0}
+    m_SelectOnDown: {fileID: 0}
+    m_SelectOnLeft: {fileID: 0}
+    m_SelectOnRight: {fileID: 0}
+  m_Transition: 1
+  m_Colors:
+    m_NormalColor: {r: 1, g: 1, b: 1, a: 1}
+    m_HighlightedColor: {r: 0.9607843, g: 0.9607843, b: 0.9607843, a: 1}
+    m_PressedColor: {r: 0.78431374, g: 0.78431374, b: 0.78431374, a: 1}
+    m_SelectedColor: {r: 0.9607843, g: 0.9607843, b: 0.9607843, a: 1}
+    m_DisabledColor: {r: 0.78431374, g: 0.78431374, b: 0.78431374, a: 0.5019608}
+    m_ColorMultiplier: 1
+    m_FadeDuration: 0.1
+  m_SpriteState:
+    m_HighlightedSprite: {fileID: 0}
+    m_PressedSprite: {fileID: 0}
+    m_SelectedSprite: {fileID: 0}
+    m_DisabledSprite: {fileID: 0}
+  m_AnimationTriggers:
+    m_NormalTrigger: Normal
+    m_HighlightedTrigger: Highlighted
+    m_PressedTrigger: Pressed
+    m_SelectedTrigger: Selected
+    m_DisabledTrigger: Disabled
+  m_Interactable: 1
+  m_TargetGraphic: {fileID: 8343020880054062986}
+  m_OnClick:
+    m_PersistentCalls:
+      m_Calls: []
 --- !u!1 &2956478068852740616
 GameObject:
   m_ObjectHideFlags: 0
@@ -12766,6 +12811,7 @@ MonoBehaviour:
   splitDecreaseButton: {fileID: 4996709440620641399}
   splitMaxButton: {fileID: 1013848439096781118}
   combineStackButton: {fileID: 4438583262695563174}
+  sortInventoryButton: {fileID: 4947710734819332199}
   autoRefresh: 1
   refreshInterval: 1
   showEquipmentDetails: 1
@@ -13665,7 +13711,7 @@ MonoBehaviour:
     m_Top: 0
     m_Bottom: 0
   m_ChildAlignment: 0
-  m_Spacing: 37.12
+  m_Spacing: -204.8
   m_ChildForceExpandWidth: 1
   m_ChildForceExpandHeight: 1
   m_ChildControlWidth: 0
@@ -20524,7 +20570,7 @@ PrefabInstance:
       objectReference: {fileID: 0}
     - target: {fileID: 7209086543831860202, guid: c56ed80641ff74ce49f91401e3eb8367, type: 3}
       propertyPath: m_AnchoredPosition.y
-      value: -42
+      value: -836.15
       objectReference: {fileID: 0}
     - target: {fileID: 8894405194986632892, guid: c56ed80641ff74ce49f91401e3eb8367, type: 3}
       propertyPath: m_AnchorMax.y
@@ -20544,7 +20590,7 @@ PrefabInstance:
       objectReference: {fileID: 0}
     - target: {fileID: 8894405194986632892, guid: c56ed80641ff74ce49f91401e3eb8367, type: 3}
       propertyPath: m_AnchoredPosition.y
-      value: -21
+      value: -418.075
       objectReference: {fileID: 0}
     m_RemovedComponents: []
     m_RemovedGameObjects: []
diff --git a/Assets/Scripts/CECHostPlayer.SortPack.cs b/Assets/Scripts/CECHostPlayer.SortPack.cs
new file mode 100644
index 0000000000..ae3371fcb3
--- /dev/null
+++ b/Assets/Scripts/CECHostPlayer.SortPack.cs
@@ -0,0 +1,208 @@
+using BrewMonster.Network;
+using BrewMonster.Scripts;
+using CSNetwork.GPDataType;
+using System.Collections.Generic;
+using static BrewMonster.Scripts.EC_Inventory;
+
+namespace BrewMonster
+{
+    public partial class CECHostPlayer
+    {
+        /// <summary>
+        /// C++ CECHostPlayer::SortPack — reorder pack via MULTI_EXCHANGE_ITEM (DlgInventory OnCommand_arrange).
+        /// </summary>
+        public void SortPack(int iPack)
+        {
+            EC_Inventory pInventory = GetPack(iPack);
+            if (pInventory == null)
+                return;
+
+            int nIvtrSize = pInventory.GetSize();
+            if (nIvtrSize <= 0)
+                return;
+
+            if (pInventory.GetEmptySlotNum() == nIvtrSize)
+                return;
+
+            for (int i = 0; i < nIvtrSize; i++)
+            {
+                var pItem = pInventory.GetItem(i, false);
+                if (pItem != null && pItem.IsFrozen())
+                    return;
+            }
+
+            for (int i = 0; i < nIvtrSize; i++)
+            {
+                var pItem = pInventory.GetItem(i, false);
+                pItem?.Freeze(true);
+            }
+
+            try
+            {
+                var vecItem = new List<int>(nIvtrSize);
+                for (int i = 0; i < nIvtrSize; i++)
+                    vecItem.Add(i);
+
+                vecItem.Sort((a, b) => ComparePackSortIndices(pInventory, a, b));
+
+                var vecExchange = new List<int>();
+                int pos = 0;
+                while (pos < nIvtrSize)
+                {
+                    int j = vecItem[pos];
+                    if (j == pos)
+                    {
+                        pos++;
+                        continue;
+                    }
+
+                    int k = vecItem[j];
+                    if (pInventory.GetItem(j, false) != null || pInventory.GetItem(k, false) != null)
+                    {
+                        vecExchange.Add(pos);
+                        vecExchange.Add(j);
+                    }
+
+                    int tmp = vecItem[pos];
+                    vecItem[pos] = vecItem[j];
+                    vecItem[j] = tmp;
+                }
+
+                if (vecExchange.Count > 0)
+                {
+                    int pairCount = vecExchange.Count / 2;
+                    for (int i = 0, j = vecExchange.Count - 1; i < j; i++, j--)
+                    {
+                        int t = vecExchange[i];
+                        vecExchange[i] = vecExchange[j];
+                        vecExchange[j] = t;
+                    }
+
+                    UnityGameSession.RequestMultiExchangeItem((byte)iPack, pairCount, vecExchange.ToArray());
+                }
+                else
+                {
+                    var pGameRun = EC_Game.GetGameRun();
+                    pGameRun?.AddChatMessage("Không cần sắp xếp kho đồ.", (int)ChatChannel.GP_CHAT_SYSTEM);
+                }
+            }
+            finally
+            {
+                for (int i = 0; i < nIvtrSize; i++)
+                {
+                    var pItem = pInventory.GetItem(i, false);
+                    pItem?.Freeze(false);
+                }
+            }
+        }
+
+        private static int ComparePackSortIndices(EC_Inventory pInventory, int index1, int index2)
+        {
+            if (DefaultPackSortLess(pInventory, index1, index2))
+                return -1;
+            if (DefaultPackSortLess(pInventory, index2, index1))
+                return 1;
+            return 0;
+        }
+
+        /// <summary>Returns true when slot <paramref name="index1"/> should appear before <paramref name="index2"/>.</summary>
+        private static bool DefaultPackSortLess(EC_Inventory pInventory, int index1, int index2)
+        {
+            if (pInventory == null)
+                return false;
+
+            EC_IvtrItem pItem1 = pInventory.GetItem(index1, false);
+            EC_IvtrItem pItem2 = pInventory.GetItem(index2, false);
+
+            if (pItem1 == null)
+                return false;
+            if (pItem2 == null)
+                return true;
+
+            int cid1 = pItem1.GetClassID();
+            int tid1 = pItem1.GetTemplateID();
+            int cid2 = pItem2.GetClassID();
+            int tid2 = pItem2.GetTemplateID();
+
+            if (cid1 != cid2)
+            {
+                int cidOrder1 = GetPackSortClassOrder(cid1);
+                int cidOrder2 = GetPackSortClassOrder(cid2);
+                if (cidOrder1 != cidOrder2)
+                    return cidOrder1 > cidOrder2;
+                return cid1 < cid2;
+            }
+
+            if (cid1 == (int)EC_IvtrItem.InventoryClassId.ICID_WEAPON)
+            {
+                if (pItem1 is CECIvtrWeapon w1 && pItem2 is CECIvtrWeapon w2)
+                {
+                    var e1 = w1.GetDBEssence();
+                    var e2 = w2.GetDBEssence();
+                    if (e1.level != e2.level)
+                        return e1.level > e2.level;
+                }
+            }
+            else if (cid1 == (int)EC_IvtrItem.InventoryClassId.ICID_ARMOR)
+            {
+                if (pItem1 is EC_IvtrArmor a1 && pItem2 is EC_IvtrArmor a2)
+                {
+                    var e1 = a1.GetDBEssence();
+                    var e2 = a2.GetDBEssence();
+                    if (e1.level != e2.level)
+                        return e1.level > e2.level;
+                }
+            }
+            else if (cid1 == (int)EC_IvtrItem.InventoryClassId.ICID_GENERALCARD)
+            {
+                if (pItem1 is EC_IvtrGeneralCard c1 && pItem2 is EC_IvtrGeneralCard c2)
+                {
+                    int t1 = c1.GetEssence().type;
+                    int t2 = c2.GetEssence().type;
+                    if (t1 != t2)
+                        return t1 < t2;
+                }
+            }
+
+            return tid1 < tid2;
+        }
+
+        private static int GetPackSortClassOrder(int cid)
+        {
+            int[] s_CIDs =
+            {
+                (int)EC_IvtrItem.InventoryClassId.ICID_WEAPON,
+                (int)EC_IvtrItem.InventoryClassId.ICID_ARROW,
+                (int)EC_IvtrItem.InventoryClassId.ICID_TOSSMAT,
+                (int)EC_IvtrItem.InventoryClassId.ICID_ARMOR,
+                (int)EC_IvtrItem.InventoryClassId.ICID_DECORATION,
+                (int)EC_IvtrItem.InventoryClassId.ICID_BIBLE,
+                (int)EC_IvtrItem.InventoryClassId.ICID_FLYSWORD,
+                (int)EC_IvtrItem.InventoryClassId.ICID_WING,
+                (int)EC_IvtrItem.InventoryClassId.ICID_GOBLIN,
+                (int)EC_IvtrItem.InventoryClassId.ICID_GOBLIN_EQUIP,
+                (int)EC_IvtrItem.InventoryClassId.ICID_FASHION,
+                (int)EC_IvtrItem.InventoryClassId.ICID_AUTOHP,
+                (int)EC_IvtrItem.InventoryClassId.ICID_AUTOMP,
+                (int)EC_IvtrItem.InventoryClassId.ICID_MEDICINE,
+                (int)EC_IvtrItem.InventoryClassId.ICID_SKILLMATTER,
+                (int)EC_IvtrItem.InventoryClassId.ICID_TARGETITEM,
+                (int)EC_IvtrItem.InventoryClassId.ICID_STONE,
+                (int)EC_IvtrItem.InventoryClassId.ICID_PETEGG,
+                (int)EC_IvtrItem.InventoryClassId.ICID_REFINETICKET,
+                (int)EC_IvtrItem.InventoryClassId.ICID_DYETICKET,
+                (int)EC_IvtrItem.InventoryClassId.ICID_GOBLIN_EXPPILL,
+                (int)EC_IvtrItem.InventoryClassId.ICID_GENERALCARD,
+                (int)EC_IvtrItem.InventoryClassId.ICID_GENERALCARD_DICE,
+            };
+
+            for (int i = 0; i < s_CIDs.Length; i++)
+            {
+                if (cid == s_CIDs[i])
+                    return s_CIDs.Length - i;
+            }
+
+            return 0;
+        }
+    }
+}
diff --git a/Assets/Scripts/CECHostPlayer.SortPack.cs.meta b/Assets/Scripts/CECHostPlayer.SortPack.cs.meta
new file mode 100644
index 0000000000..ef96f78e3a
--- /dev/null
+++ b/Assets/Scripts/CECHostPlayer.SortPack.cs.meta
@@ -0,0 +1,2 @@
+fileFormatVersion: 2
+guid: 22d7c6cd009100d44956b805ed093795
\ No newline at end of file