将Ubuntu 9.10升级到10.04，我们先换10.04的源：
sudo gedit /etc/apt/sources.list
在打开的文档里将原 来的内容全部删除，添加下面列表中最适合你的源（注意不要全部添加），选择一个最合适你的即可，复制到你的列表中，然后保存列表。
Ubuntu 10.04源列表：
台湾 代码:
deb lucid main universe restricted multiverse
deb-src lucid main universe restricted multiverse
deb lucid-security universe main multiverse restricted
deb-src lucid-security universe main multiverse restricted
deb lucid-updates universe main multiverse restricted
deb-src lucid-updates universe main multiverse restricted
SRT Sources 代码:
deb lucid main restricted universe multiverse
deb lucid-security main restricted universe multiverse
deb lucid-updates main restricted universe multiverse
deb lucid-proposed main restricted universe multiverse
deb lucid-backports main restricted universe multiverse
deb-src lucid main restricted universe multiverse
deb-src lucid-security main restricted universe multiverse
deb-src lucid-updates main restricted universe multiverse
deb-src lucid-proposed main restricted universe multiverse
deb-src lucid-backports main restricted universe multiverse
网易（速度很快）代码:
deb lucid main universe restricted multiverse
deb-src lucid main universe restricted multiverse
deb lucid-security universe main multiverse restricted
deb-src lucid-security universe main multiverse restricted
deb lucid-updates universe main multiverse restricted
deb lucid-proposed universe main multiverse restricted
deb-src lucid-proposed universe main multiverse restricted
deb lucid-backports universe main multiverse restricted
deb-src lucid-backports universe main multiverse restricted
deb-src lucid-updates universe main multiverse restricted
ubuntu官方上海源，提供 Kernel，Hiweed，ubuntu 代码:
deb lucid main universe restricted multiverse
deb-src lucid main universe restricted multiverse
deb lucid-security universe main multiverse restricted
deb-src lucid-security universe main multiverse restricted
deb lucid-updates universe main multiverse restricted
deb lucid-proposed universe main multiverse restricted
deb-src lucid-proposed universe main multiverse restricted
deb lucid-backports universe main multiverse restricted
deb-src lucid-backports universe main multiverse restricted
deb-src lucid-updates universe main multiverse restricted
搜狐 代码:
deb lucid main universe restricted multiverse
deb-src lucid main universe restricted multiverse
deb lucid-security universe main multiverse restricted
deb-src lucid-security universe main multiverse restricted
deb lucid-updates universe main multiverse restricted
deb lucid-proposed universe main multiverse restricted
deb-src lucid-proposed universe main multiverse restricted
deb lucid-backports universe main multiverse restricted
deb-src lucid-backports universe main multiverse restricted
deb-src lucid-updates universe main multiverse restricted
骨头源，骨头源是bones7456架设的一个Ubuntu源 ，提供ubuntu,deepin 代码:
deb lucid main universe restricted multiverse
deb-src lucid main universe restricted multiverse
deb lucid-security universe main multiverse restricted
deb-src lucid-security universe main multiverse restricted
deb lucid-updates universe main multiverse restricted
deb lucid-proposed universe main multiverse restricted
deb-src lucid-proposed universe main multiverse restricted
deb lucid-backports universe main multiverse restricted
deb-src lucid-backports universe main multiverse restricted
deb-src lucid-updates universe main multiverse restricted
然后我们更新源信息：
sudo apt-get update
接着我们开始升级：
sudo apt-get upgrade
OK!
以下是官方给出的方法： 每 6 个月 Ubuntu 就会发布新版本；当有新版可供下载时更新管理器会通知您。要检查新版本：
1.打开软件源(系统 ? 系统管理 ? 软件源)然后选择 更新 标签。
2.在发行版本升级下, 确定普通版本已被选择，然后单击关闭。
3.打开系统管理器(系统 ? 系统管理 ? 更新管理器), 单击 检查 如果提示的话输入密码。等待可用的更新下载完毕。
4.当新版本的 Ubuntu 发布时，窗口上方会出现关于有新版本发布的提示。
5. 要升级到最新的版本，您需要保存好您的文档并单击更新管理器中的 升级 按钮。
版本升级通常会花费一段时间才能完成。典型情况下，必须下载并安装大约700MB的软件包，但实际大小依赖于您计算机上已经安装的软件包数量。
您只能从第二新的版本升级到 Ubuntu 的最新版。如果您有一个较旧的版本，您必须升级到下一个版本，然后继续升级，直到最新版。例如，7.10 版的用户必须升级到 8.04 版，然后才能升级到 8.10 版。但对于 LTS(长期支持)版例外。您可以从前一个 LTS 版直接升级到当前版本
升级到开发版