diff --git a/WebApi_data_value/Controllers/Yuntech_parking_user_listController.cs b/WebApi_data_value/Controllers/Yuntech_parking_user_listController.cs
index fc55c2e..39f9e5e 100644
--- a/WebApi_data_value/Controllers/Yuntech_parking_user_listController.cs
+++ b/WebApi_data_value/Controllers/Yuntech_parking_user_listController.cs
@@ -120,24 +120,34 @@ namespace WebApi_data_value.Controllers
           {
               return Problem("Entity set 'SqlContext.yuntech_parking_user_list'  is null.");
           }
-            _context.yuntech_parking_user_list.Add(yuntech_parking_user_list);
-            try
+            var license_plate_number = yuntech_parking_user_list.user_license_plate_number;
+            var data = await(from c in _context.yuntech_parking_user_list
+                             where c.user_license_plate_number == license_plate_number
+                             select c
+                             ).FirstOrDefaultAsync();
+            if (data == null)
             {
-                await _context.SaveChangesAsync();
-            }
-            catch (DbUpdateException)
-            {
-                if (Yuntech_parking_user_listExists(yuntech_parking_user_list.user_license_plate_number))
+                _context.yuntech_parking_user_list.Add(yuntech_parking_user_list);
+                try
                 {
-                    return Conflict();
+                    await _context.SaveChangesAsync();
                 }
-                else
+                catch (DbUpdateException)
                 {
-                    throw;
+                    if (Yuntech_parking_user_listExists(yuntech_parking_user_list.user_license_plate_number))
+                    {
+                        return Conflict();
+                    }
+                    else
+                    {
+                        throw;
+                    }
                 }
-            }
 
-            return CreatedAtAction("GetYuntech_parking_user_list", new { id = yuntech_parking_user_list.user_license_plate_number }, yuntech_parking_user_list);
+                return Ok("ok");
+            }
+            
+            return Ok("車牌重複");
         }
         #endregion