diff --git a/qcloud_cos/demo.py b/qcloud_cos/demo.py
index f6c9f3be..a6509f50 100644
--- a/qcloud_cos/demo.py
+++ b/qcloud_cos/demo.py
@@ -11,6 +11,7 @@
 # cos最新可用地域,参照https://www.qcloud.com/document/product/436/6224
 
 # 设置用户属性, 包括secret_id, secret_key, region
+# appid已在配置中移除,请在参数Bucket中带上appid。Bucket由bucketname-appid组成
 secret_id = 'AKID15IsskiBQACGbAo6WhgcQbVls7HmuG00'     # 替换为用户的secret_id
 secret_key = 'csivKvxxrMvSvQpMWHuIz12pThQQlWRW'     # 替换为用户的secret_key
 region = 'ap-beijing-1'    # 替换为用户的region