sudo cp /etc/apt/sources.list /etc/apt/sources.list.bak #备份更新源
sudo gedit /etc/apt/sources.list #编辑更新源，在源文件的末尾加上下面的源，选择自己的线路。
如果你是网通用户请更换下列更新源：
deb
http://archive.ubuntu.com/ubuntu/ gutsy main restricted universe multiverse
deb
http://archive.ubuntu.com/ubuntu/ gutsy-security main restricted universe multiverse
deb
http://archive.ubuntu.com/ubuntu/ gutsy-updates main restricted universe multiverse
deb
http://archive.ubuntu.com/ubuntu/ gutsy-proposed main restricted universe multiverse
deb
http://archive.ubuntu.com/ubuntu/ gutsy-backports main restricted universe multiverse
deb-src
http://archive.ubuntu.com/ubuntu/ gutsy main restricted universe multiverse
deb-src
http://archive.ubuntu.com/ubuntu/ gutsy-security main restricted universe multiverse
deb-src
http://archive.ubuntu.com/ubuntu/ gutsy-updates main restricted universe multiverse
deb-src
http://archive.ubuntu.com/ubuntu/ gutsy-proposed main restricted universe multiverse
deb-src
http://archive.ubuntu.com/ubuntu/ gutsy-backports main restricted universe multiverse
如果你是电信的用户，请更换下列的源：
#cn99.com 源更新服务器（江苏省常州市电信，推荐电信用户使用，我自己是南方电信1M带宽的用户，更新速度平均有100K）：
deb
http://ubuntu.cn99.com/ubuntu/ gutsy main restricted universe multiverse
deb
http://ubuntu.cn99.com/ubuntu/ gutsy-security main restricted universe multiverse
deb
http://ubuntu.cn99.com/ubuntu/ gutsy-updates main restricted universe multiverse
deb
http://ubuntu.cn99.com/ubuntu/ gutsy-proposed main restricted universe multiverse
deb
http://ubuntu.cn99.com/ubuntu/ gutsy-backports main restricted universe multiverse
deb-src
http://ubuntu.cn99.com/ubuntu/ gutsy main restricted universe multiverse
deb-src
http://ubuntu.cn99.com/ubuntu/ gutsy-security main restricted universe multiverse
deb-src
http://ubuntu.cn99.com/ubuntu/ gutsy-updates main restricted universe multiverse
deb-src
http://ubuntu.cn99.com/ubuntu/ gutsy-proposed main restricted universe multiverse
deb-src
http://ubuntu.cn99.com/ubuntu/ gutsy-backports main restricted universe multiverse
#Mirror.lupaworld.com 源更新服务器（浙江省杭州市双线服务器，网通同电信都可以用，亚洲地区官方更新服务器）：
deb
http://mirror.lupaworld.com/ubuntu gutsy main restricted universe multiverse
deb
http://mirror.lupaworld.com/ubuntu gutsy-security main restricted universe multiverse
deb
http://mirror.lupaworld.com/ubuntu gutsy-updates main restricted universe multiverse
deb
http://mirror.lupaworld.com/ubuntu gutsy-backports main restricted universe multiverse
deb-src
http://mirror.lupaworld.com/ubuntu gutsy main restricted universe multiverse
deb-src
http://mirror.lupaworld.com/ubuntu gutsy-security main restricted universe multiverse
deb-src
http://mirror.lupaworld.com/ubuntu gutsy-updates main restricted universe multiverse
deb-src
http://mirror.lupaworld.com/ubuntu gutsy-backports main restricted universe multiverse
编辑完以后
sudo apt-get update
升级完成以后你再到 “系统－系统管理－语言支持” 里面把 “Chinese” 勾选上。