1.sudo gedit /etc/apt/sources.list
编辑你的源列表，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。
2.sudo apt-get update 更新源列表信息
可以在运行“sudo apt-get update ”时查看一下错误信息，把不能连接的源删除再重新运行“sudo apt-get update ”。
3.sudo apt-get upgrade 升 级或者用ubuntu自带的更新管理器升级也可
Ubuntu 10.04源列表：
网易（速度很快）
deb http://mirrors.163.com/ubuntu/ lucid main universe restricted multiverse
deb-src http://mirrors.163.com/ubuntu/ lucid main universe restricted multiverse
deb http://mirrors.163.com/ubuntu/ lucid-security universe main multiverse restricted
deb-src http://mirrors.163.com/ubuntu/ lucid-security universe main multiverse restricted
deb http://mirrors.163.com/ubuntu/ lucid-updates universe main multiverse restricted
deb http://mirrors.163.com/ubuntu/ lucid-proposed universe main multiverse restricted
deb-src http://mirrors.163.com/ubuntu/ lucid-proposed universe main multiverse restricted
deb http://mirrors.163.com/ubuntu/ lucid-backports universe main multiverse restricted
deb-src http://mirrors.163.com/ubuntu/ lucid-backports universe main multiverse restricted
deb-src http://mirrors.163.com/ubuntu/ lucid-updates universe main multiverse restricted
搜狐
deb http://mirrors.shlug.org/ubuntu/ lucid main universe restricted multiverse
deb-src http://mirrors.shlug.org/ubuntu/ lucid main universe restricted multiverse
deb http://mirrors.shlug.org/ubuntu/ lucid-security universe main multiverse restricted
deb-src http://mirrors.shlug.org/ubuntu/ lucid-security universe main multiverse restricted
deb http://mirrors.shlug.org/ubuntu/ lucid-updates universe main multiverse restricted
deb http://mirrors.shlug.org/ubuntu/ lucid-proposed universe main multiverse restricted
deb-src http://mirrors.shlug.org/ubuntu/ lucid-proposed universe main multiverse restricted
deb http://mirrors.shlug.org/ubuntu/ lucid-backports universe main multiverse restricted
deb-src http://mirrors.shlug.org/ubuntu/ lucid-backports universe main multiverse restricted
deb-src http://mirrors.shlug.org/ubuntu/ lucid-updates universe main multiverse restricted
SRT Sources
deb http://ubuntu.srt.cn/ubuntu/ lucid main restricted universe multiverse
deb http://
ubuntu.srt.cn/ubuntu/ lucid-security main restricted universe multiverse
deb http://ubuntu.srt.cn/ubuntu/ lucid-updates main restricted universe multiverse
deb http://ubuntu.srt.cn/ubuntu/ lucid-proposed main restricted universe multiverse
deb http://ubuntu.srt.cn/ubuntu/ lucid-backports main restricted universe multiverse
deb-src http://ubuntu.srt.cn/ubuntu/ lucid main restricted universe multiverse
deb-src http://ubuntu.srt.cn/ubuntu/ lucid-security main restricted universe multiverse
deb-src http://ubuntu.srt.cn/ubuntu/ lucid-updates main restricted universe multiverse
deb-src http://ubuntu.srt.cn/ubuntu/ lucid-proposed main restricted universe multiverse
deb-src http://ubuntu.srt.cn/ubuntu/ lucid-backports main restricted universe multiverse
ubuntu官方上海源
deb http://mirror.rootguide.org/ubuntu/ lucid main universe restricted multiverse
deb-src http://mirror.rootguide.org/ubuntu/ lucid main universe restricted multiverse
deb http://mirror.rootguide.org/ubuntu/ lucid-security universe main multiverse restricted
deb-src http://mirror.rootguide.org/ubuntu/ lucid-security universe main multiverse restricted
deb http://mirror.rootguide.org/ubuntu/ lucid-updates universe main multiverse restricted
deb http://mirror.rootguide.org/ubuntu/ lucid-proposed universe main multiverse restricted
deb-src http://mirror.rootguide.org/ubuntu/ lucid-proposed universe main multiverse restricted
deb http://mirror.rootguide.org/ubuntu/ lucid-backports universe main multiverse restricted
deb-src http://mirror.rootguide.org/ubuntu/ lucid-backports universe main multiverse restricted
deb-src http://mirror.rootguide.org/ubuntu/ lucid-updates universe main multiverse restricted
