diff --git a/Assets/Scripts/PlayerActionSystem.cs b/Assets/Scripts/PlayerActionSystem.cs
index 77a8064..28ca514 100644
--- a/Assets/Scripts/PlayerActionSystem.cs
+++ b/Assets/Scripts/PlayerActionSystem.cs
@@ -87,6 +87,9 @@ namespace Northbound
 
         private void OnAttack(InputAction.CallbackContext context)
         {
+            // UI가 열려있으면 액션 실행 안 함
+            if (UpgradeListPopup.IsOpen) return;
+
             ExecuteAction("Attack");
         }
 
diff --git a/Assets/Scripts/UI/UpgradeListPopup.cs b/Assets/Scripts/UI/UpgradeListPopup.cs
index 6527d3b..13701e0 100644
--- a/Assets/Scripts/UI/UpgradeListPopup.cs
+++ b/Assets/Scripts/UI/UpgradeListPopup.cs
@@ -12,6 +12,10 @@ namespace Northbound
     /// </summary>
     public class UpgradeListPopup : MonoBehaviour
     {
+        // 싱글톤 인스턴스 (UI 열림 상태 확인용)
+        private static UpgradeListPopup _instance;
+        public static bool IsOpen => _instance != null && _instance.gameObject.activeSelf;
+
         [Header("References")]
         [SerializeField] private Transform _contentParent;
         [SerializeField] private GameObject _listItemPrefab;
@@ -24,6 +28,8 @@ namespace Northbound
 
         private void Awake()
         {
+            _instance = this;
+
             if (_closeButton != null)
             {
                 _closeButton.onClick.AddListener(Close);
@@ -169,6 +175,10 @@ namespace Northbound
 
         private void OnDestroy()
         {
+            if (_instance == this)
+            {
+                _instance = null;
+            }
             ClearList();
         }
     }