diff --git a/problem/views/admin.py b/problem/views/admin.py
index ee04dc13b..b713c345c 100644
--- a/problem/views/admin.py
+++ b/problem/views/admin.py
@@ -32,12 +32,14 @@
 
 
 class TestCaseZipProcessor(object):
-    def process_zip(self, uploaded_zip_file, spj, dir=""):
+    def process_zip(self, uploaded_zip_file, spj, dir=None):
         try:
             zip_file = zipfile.ZipFile(uploaded_zip_file, "r")
         except zipfile.BadZipFile:
             raise APIError("Bad zip file")
         name_list = zip_file.namelist()
+        if not dir:
+            dir = self.judge_dir(name_list)        
         test_case_list = self.filter_name_list(name_list, spj=spj, dir=dir)
         if not test_case_list:
             raise APIError("Empty file")
@@ -110,6 +112,24 @@ def filter_name_list(self, name_list, spj, dir=""):
                 else:
                     return sorted(ret, key=natural_sort_key)
 
+    def judge_dir(self, name_list):
+        is_native = True
+        for i, item_i in enumerate(name_list):
+            if "/" not in item_i:
+                return ""
+            if not is_native:
+                break
+            for j, item_j in enumerate(name_list):
+                if (item_i not in item_j):
+                    break
+                if (j == len(name_list) - 1):
+                    is_native = False
+        if not is_native:
+            dir = name_list[0]
+        else:
+            dir = name_list[0].split("/")[0]+"/"
+        return dir
+
 
 class TestCaseAPI(CSRFExemptAPIView, TestCaseZipProcessor):
     request_parsers = ()