diff --git a/Software/System/Linux/Editions/Ubuntu/Ubuntu_系统升级.md b/Software/System/Linux/Editions/Ubuntu/Ubuntu_系统升级.md
index ac79a7a..5ffb9ee 100644
--- a/Software/System/Linux/Editions/Ubuntu/Ubuntu_系统升级.md
+++ b/Software/System/Linux/Editions/Ubuntu/Ubuntu_系统升级.md
@@ -2,7 +2,7 @@
 
 *不是升级软件包，而是升级整个系统。*
 
-## 1.查看当前系统版本
+## 1. 查看当前系统版本
 
 ```bash
 lsb_release -a
@@ -10,7 +10,7 @@ lsb_release -a
 cat /etc/issue
 ```
 
-## 2.从命令行升级
+## 2. 从命令行升级
 
 先升级软件包
 
@@ -39,3 +39,13 @@ sudo do-release-upgrade
 ```
 
 如果升级过程中出现了“Upgrade tool  404  Not Found [IP: 59.80.44.45 80]”字样错误，可以尝试修改 /etc/apt/sources.list 为国内（如清华）镜像。
+
+## 3. 关闭自动升级
+
+修改 /etc/apt/apt.conf.d/10periodic 文件中的 APT::Periodic::Update-Package-Lists 为零。
+
+```bash
+APT::Periodic::Update-Package-Lists "0";
+APT::Periodic::Download-Upgradeable-Packages "0";
+APT::Periodic::AutocleanInterval "0";
+```