diff --git a/AddTitleNumber.py b/AddTitleNumber.py
index 2c67a12..476d20b 100644
--- a/AddTitleNumber.py
+++ b/AddTitleNumber.py
@@ -114,7 +114,7 @@ def create_markdown_file_with_number(f):
     file_and_dir = os.listdir(path)
     print('当前目录下的Markdown文件：')
     for item in file_and_dir:
-        if item.split('.')[-1] in ['md','Md','MD','Markdown','markdown'] and os.path.isfile(item):
+        if item.split('.')[-1].lower() in ['md','mdown','markdown'] and os.path.isfile(item):
             print(item)
     file_name = input('请输入文件名(含后缀)\n')
 else:
diff --git a/TOC.py b/TOC.py
index 0645211..b7319ee 100644
--- a/TOC.py
+++ b/TOC.py
@@ -64,7 +64,7 @@ def creat_file_with_toc(f):
         file_and_dir = os.listdir(path)
         print('当前目录下的Markdown文件：')
         for item in file_and_dir:
-            if item.split('.')[-1] in ['md','Md','MD','Markdown','markdown'] and os.path.isfile(item):
+            if item.split('.')[-1].lower() in ['md','mdown','markdown'] and os.path.isfile(item):
                 print(item)
         file_name = input('请输入文件名(含后缀)\n')
     else: