安装好ubuntu 12.04之后，可以联网之后，马上要做的最重要的事情之一就是配置更新源列表，这样以后安装更新或者软件才可以获得较好的下载速度。
首先，备份一下原来的源地址列表文件
sudo cp /etc/apt/sources.list /etc/apt/sources.list.old
然后进行修改
sudo gedit /etc/apt/sources.list
可以在里面添加资源地址，我是直接覆盖掉原来的。
添加好后保存，再输入 sudo apt-get update 就可以更新了，等着慢慢下载东西吧。我虽然选了一个网易的和一个中科大的源，无奈那天网速不给力，还是花了差不多两个小时。
下面是网上找到的一些较好的源，有大型网站的，也有教育网的，可以根据自己的情况添加两三个即可。
#网易的源（速度很快）
deb http://mirrors.163.com/ubuntu/ precise main universe restricted multiverse
deb-src http://mirrors.163.com/ubuntu/ precise main universe restricted multiverse
deb http://mirrors.163.com/ubuntu/ precise-security universe main multiverse restricted
deb-src http://mirrors.163.com/ubuntu/ precise-security universe main multiverse restricted
deb http://mirrors.163.com/ubuntu/ precise-updates universe main multiverse restricted
deb http://mirrors.163.com/ubuntu/ precise-proposed universe main multiverse restricted
deb-src http://mirrors.163.com/ubuntu/ precise-proposed universe main multiverse restricted
deb http://mirrors.163.com/ubuntu/ precise-backports universe main multiverse restricted
deb-src http://mirrors.163.com/ubuntu/ precise-backports universe main multiverse restricted
deb-src http://mirrors.163.com/ubuntu/ precise-updates universe main multiverse restricted
#搜狐的源
deb http://mirrors.sohu.com/ubuntu/ precise main restricted
deb-src http://mirrors.sohu.com/ubuntu/ precise main restricted
deb http://mirrors.sohu.com/ubuntu/ precise-updates main restricted
deb-src http://mirrors.sohu.com/ubuntu/ precise-updates main restricted
deb http://mirrors.sohu.com/ubuntu/ precise universe
deb-src http://mirrors.sohu.com/ubuntu/ precise universe
deb http://mirrors.sohu.com/ubuntu/ precise-updates universe
deb-src http://mirrors.sohu.com/ubuntu/ precise-updates universe
deb http://mirrors.sohu.com/ubuntu/ precise multiverse
deb-src http://mirrors.sohu.com/ubuntu/ precise multiverse
deb http://mirrors.sohu.com/ubuntu/ precise-updates multiverse
deb-src http://mirrors.sohu.com/ubuntu/ precise-updates multiverse
deb http://mirrors.sohu.com/ubuntu/ precise-backports main restricted universe multiverse
deb-src http://mirrors.sohu.com/ubuntu/ precise-backports main restricted universe multiverse
deb http://mirrors.sohu.com/ubuntu/ precise-security main restricted
deb-src http://mirrors.sohu.com/ubuntu/ precise-security main restricted
deb http://mirrors.sohu.com/ubuntu/ precise-security universe
deb-src http://mirrors.sohu.com/ubuntu/ precise-security universe
deb http://mirrors.sohu.com/ubuntu/ precise-security multiverse
deb-src http://mirrors.sohu.com/ubuntu/ precise-security multiverse
deb http://extras.ubuntu.com/ubuntu precise main
deb-src http://extras.ubuntu.com/ubuntu precise main
#台湾源
deb http://tw.archive.ubuntu.com/ubuntu/ precise main universe restricted multiverse
deb-src http://tw.archive.ubuntu.com/ubuntu/ precise main universe restricted multiverse
deb http://tw.archive.ubuntu.com/ubuntu/ precise-security universe main multiverse restricted
deb-src http://tw.archive.ubuntu.com/ubuntu/ precise-security universe main multiverse restricted
deb http://tw.archive.ubuntu.com/ubuntu/ precise-updates universe main multiverse restricted
deb-src http://tw.archive.ubuntu.com/ubuntu/ precise-updates universe main multiverse restricted
#骨头源，骨头源是bones7456架设的一个Ubuntu源 ，提供ubuntu,deepin
deb http://ubuntu.srt.cn/ubuntu/ precise main universe restricted multiverse
deb-src http://ubuntu.srt.cn/ubuntu/ precise main universe restricted multiverse
deb http://ubuntu.srt.cn/ubuntu/ precise-security universe main multiverse restricted
deb-src http://ubuntu.srt.cn/ubuntu/ precise-security universe main multiverse restricted
deb http://ubuntu.srt.cn/ubuntu/ precise-updates universe main multiverse restricted
deb http://ubuntu.srt.cn/ubuntu/ precise-proposed universe main multiverse restricted
deb-src http://ubuntu.srt.cn/ubuntu/ precise-proposed universe main multiverse restricted
deb http://ubuntu.srt.cn/ubuntu/ precise-backports universe main multiverse restricted
deb-src http://ubuntu.srt.cn/ubuntu/ precise-backports universe main multiverse restricted
deb-src http://ubuntu.srt.cn/ubuntu/ precise-updates universe main multiverse restricted
#mirror.lupaworld.com的源，速度很快
deb http://mirror.lupaworld.com/ubuntu/archive/ precise main restricted universe multiverse
deb http://mirror.lupaworld.com/ubuntu/archive/ precise-security main restricted universe multiverse
deb http://mirror.lupaworld.com/ubuntu/archive/ precise-updates main restricted universe multiverse
deb http://mirror.lupaworld.com/ubuntu/archive/ precise-backports main restricted universe multiverse
deb http://mirror.lupaworld.com/ubuntu/ubuntu-cn/ precise main restricted universe multiverse
#ubuntu.cn99.com源（推荐）:
deb http://ubuntu.cn99.com/ubuntu/ precise main restricted universe multiverse
deb http://ubuntu.cn99.com/ubuntu/ precise-updates main restricted universe multiverse
deb http://ubuntu.cn99.com/ubuntu/ precise-security main restricted universe multiverse
deb http://ubuntu.cn99.com/ubuntu/ precise-backports main restricted universe multiverse
deb http://ubuntu.cn99.com/ubuntu-cn/ precise main restricted universe multiverse
#教育网源
#电子科技大学
deb http://ubuntu.uestc.edu.cn/ubuntu/ precise main restricted universe multiverse
deb http://ubuntu.uestc.edu.cn/ubuntu/ precise-backports main restricted universe multiverse
deb http://ubuntu.uestc.edu.cn/ubuntu/ precise-proposed main restricted universe multiverse
deb http://ubuntu.uestc.edu.cn/ubuntu/ precise-security main restricted universe multiverse
deb http://ubuntu.uestc.edu.cn/ubuntu/ precise-updates main restricted universe multiverse
deb-src http://ubuntu.uestc.edu.cn/ubuntu/ precise main restricted universe multiverse
deb-src http://ubuntu.uestc.edu.cn/ubuntu/ precise-backports main restricted universe multiverse
deb-src http://ubuntu.uestc.edu.cn/ubuntu/ precise-proposed main restricted universe multiverse
deb-src http://ubuntu.uestc.edu.cn/ubuntu/ precise-security main restricted universe multiverse
deb-src http://ubuntu.uestc.edu.cn/ubuntu/ precise-updates main restricted universe multiverse
#中国科技大学
deb http://debian.ustc.edu.cn/ubuntu/ precise main restricted universe multiverse
deb http://debian.ustc.edu.cn/ubuntu/ precise-backports restricted universe multiverse
deb http://debian.ustc.edu.cn/ubuntu/ precise-proposed main restricted universe multiverse
deb http://debian.ustc.edu.cn/ubuntu/ precise-security main restricted universe multiverse
deb http://debian.ustc.edu.cn/ubuntu/ precise-updates main restricted universe multiverse
deb-src http://debian.ustc.edu.cn/ubuntu/ precise main restricted universe multiverse
deb-src http://debian.ustc.edu.cn/ubuntu/ precise-backports main restricted universe multiverse
deb-src http://debian.ustc.edu.cn/ubuntu/ precise-proposed main restricted universe multiverse
deb-src http://debian.ustc.edu.cn/ubuntu/ precise-security main restricted universe multiverse
deb-src http://debian.ustc.edu.cn/ubuntu/ precise-updates main restricted universe multiverse
#北京理工大学
deb http://mirror.bjtu.edu.cn/ubuntu/ precise main multiverse restricted universe
deb http://mirror.bjtu.edu.cn/ubuntu/ precise-backports main multiverse restricted universe
deb http://mirror.bjtu.edu.cn/ubuntu/ precise-proposed main multiverse restricted universe
deb http://mirror.bjtu.edu.cn/ubuntu/ precise-security main multiverse restricted universe
deb http://mirror.bjtu.edu.cn/ubuntu/ precise-updates main multiverse restricted universe
deb-src http://mirror.bjtu.edu.cn/ubuntu/ precise main multiverse restricted universe
deb-src http://mirror.bjtu.edu.cn/ubuntu/ precise-backports main multiverse restricted universe
deb-src http://mirror.bjtu.edu.cn/ubuntu/ precise-proposed main multiverse restricted universe
deb-src http://mirror.bjtu.edu.cn/ubuntu/ precise-security main multiverse restricted universe
deb-src http://mirror.bjtu.edu.cn/ubuntu/ precise-updates main multiverse restricted universe
#兰州大学
deb ftp://mirror.lzu.edu.cn/ubuntu/ precise main multiverse restricted universe
deb ftp://mirror.lzu.edu.cn/ubuntu/ precise-backports main multiverse restricted universe
deb ftp://mirror.lzu.edu.cn/ubuntu/ precise-proposed main multiverse restricted universe
deb ftp://mirror.lzu.edu.cn/ubuntu/ precise-security main multiverse restricted universe
deb ftp://mirror.lzu.edu.cn/ubuntu/ precise-updates main multiverse restricted universe
deb ftp://mirror.lzu.edu.cn/ubuntu-cn/ precise main multiverse restricted universe
#上海交通大学
deb http://ftp.sjtu.edu.cn/ubuntu/ precise main multiverse restricted universe
deb http://ftp.sjtu.edu.cn/ubuntu/ precise-backports main multiverse restricted universe
deb http://ftp.sjtu.edu.cn/ubuntu/ precise-proposed main multiverse restricted universe
deb http://ftp.sjtu.edu.cn/ubuntu/ precise-security main multiverse restricted universe
deb http://ftp.sjtu.edu.cn/ubuntu/ precise-updates main multiverse restricted universe
deb http://ftp.sjtu.edu.cn/ubuntu-cn/ precise main multiverse restricted universe
deb-src http://ftp.sjtu.edu.cn/ubuntu/ precise main multiverse restricted universe
deb-src http://ftp.sjtu.edu.cn/ubuntu/ precise-backports main multiverse restricted universe
deb-src http://ftp.sjtu.edu.cn/ubuntu/ precise-proposed main multiverse restricted universe
deb-src http://ftp.sjtu.edu.cn/ubuntu/ precise-security main multiverse restricted universe
deb-src http://ftp.sjtu.edu.cn/ubuntu/ precise-updates main multiverse restricted universe
