Ubuntu軟件源的修改比較簡單，一種方法是直接修改軟件軟列表：只需要把所需的軟件源添加到或直接替換原來的系統源列表就可以，列表文件就是/etc/apt/sources.list。在終端執行以下命令：

#進入所在目錄：cd /etc/apt/#備份源列表：sudo cp sources.list sources.list.bak#編輯源列表：sudo gedit /etc/apt/sources.list

如果希望把某一個軟件源添加到列表，則只需要一個命令就好，比如在Ubuntu上安裝搜狗輸入法的時候，可能需要更新Fcitx，需要通過下面的命令添加其軟件源：

sudo add-apt-repository ppa:fcitx-team/nightly

最后面的就是Fcitx的官方源了。

下面是一些國內比較好的源，請按照第一種方法添加。從以下各服務器列表內容中選擇一段替換文件中的所有內容，也可以加在后面或前面，甚至可以添加多個。請根據自己網絡環境設置更新服務器，以達到最快的速度。

　　在這里要說明一下，關于有些人使用下面的源后，更新軟件列表時提示下面這樣的錯誤：

W: Failed to fetch http://debian.ustc.edu.cn/ubuntu/dists/raring-updates/restricted/binary-i386/Packages  404  Not Found [ip: 202.141.160.110 80]W: Failed to fetch http://debian.ustc.edu.cn/ubuntu/dists/raring-updates/universe/binary-i386/Packages  404  Not Found [IP: 202.141.160.110 80]W: Failed to fetch http://debian.ustc.edu.cn/ubuntu/dists/raring-updates/multiverse/binary-i386/Packages  404  Not Found [IP: 202.141.160.110 80]

　　原因在于選用的源已經停止支持，大家要注意軟件源列表中的信息，每一個版本都有對應的軟件源，比如deb http://mirrors.163.com/ubuntu/ PRecise main restricted 是12.04的軟件源，而deb http://mirrors.163.com/ubuntu/ raring main universe restricted multiverse是13.04的軟件源，建議大家盡量選用長期支持版的軟件源，當然更建議大家使用長期支持版的系統。

　　如果下面的源和你的版本不匹配也沒關系，把precise替換成相應的版本號就好，不過有些非長期支持版可能還是不能用，提示404錯誤，我也是突然發現我使用了13.04的源，而且網易和中科大的源都不能用了才發現這一點。

　　下面這個是網易的12.04的源。具體大家可以參考網易的手冊：http://mirrors.163.com/.help/ubuntu.html

#網易163的源，ubuntu12.04，更新很快deb http://mirrors.163.com/ubuntu/ precise main restricteddeb-src http://mirrors.163.com/ubuntu/ precise main restricteddeb http://mirrors.163.com/ubuntu/ precise-updates main restricteddeb-src http://mirrors.163.com/ubuntu/ precise-updates main restricteddeb http://mirrors.163.com/ubuntu/ precise-updates universedeb-src http://mirrors.163.com/ubuntu/ precise-updates universedeb http://mirrors.163.com/ubuntu/ precise multiversedeb-src http://mirrors.163.com/ubuntu/ precise multiversedeb http://mirrors.163.com/ubuntu/ precise-updates multiversedeb-src http://mirrors.163.com/ubuntu/ precise-updates multiversedeb http://mirrors.163.com/ubuntu/ precise-backports main restricted universe multiversedeb-src http://mirrors.163.com/ubuntu/ precise-backports main restricted universe multiversedeb http://mirrors.163.com/ubuntu/ precise-security main restricteddeb-src http://mirrors.163.com/ubuntu/ precise-security main restricteddeb http://mirrors.163.com/ubuntu/ precise-security universedeb-src http://mirrors.163.com/ubuntu/ precise-security universedeb http://mirrors.163.com/ubuntu/ precise-security multiversedeb-src http://mirrors.163.com/ubuntu/ precise-security multiversedeb http://extras.ubuntu.com/ubuntu precise maindeb-src http://extras.ubuntu.com/ubuntu precise main

#中國科學技術大學，我一直用，真的很快deb http://debian.ustc.edu.cn/ubuntu/ precise main restricted universe multiversedeb http://debian.ustc.edu.cn/ubuntu/ precise-backports restricted universe multiversedeb http://debian.ustc.edu.cn/ubuntu/ precise-proposed main restricted universe multiversedeb http://debian.ustc.edu.cn/ubuntu/ precise-security main restricted universe multiversedeb http://debian.ustc.edu.cn/ubuntu/ precise-updates main restricted universe multiversedeb-src http://debian.ustc.edu.cn/ubuntu/ precise main restricted universe multiversedeb-src http://debian.ustc.edu.cn/ubuntu/ precise-backports main restricted universe multiversedeb-src http://debian.ustc.edu.cn/ubuntu/ precise-proposed main restricted universe multiversedeb-src http://debian.ustc.edu.cn/ubuntu/ precise-security main restricted universe multiversedeb-src http://debian.ustc.edu.cn/ubuntu/ precise-updates main restricted universe multiverse

#臺灣源deb http://tw.archive.ubuntu.com/ubuntu/ precise main universe restricted multiversedeb-src http://tw.archive.ubuntu.com/ubuntu/ precise main universe restricted multiversedeb http://tw.archive.ubuntu.com/ubuntu/ precise-security universe main multiverse restricteddeb-src http://tw.archive.ubuntu.com/ubuntu/ precise-security universe main multiverse restricteddeb http://tw.archive.ubuntu.com/ubuntu/ precise-updates universe main multiverse restricteddeb-src http://tw.archive.ubuntu.com/ubuntu/ precise-updates universe main multiverse restricted

#骨頭源，骨頭源是bones7456架設的一個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 restricteddeb-src http://ubuntu.srt.cn/ubuntu/ precise-security universe main multiverse restricteddeb http://ubuntu.srt.cn/ubuntu/ precise-updates universe main multiverse restricteddeb http://ubuntu.srt.cn/ubuntu/ precise-proposed universe main multiverse restricteddeb-src http://ubuntu.srt.cn/ubuntu/ precise-proposed universe main multiverse restricteddeb http://ubuntu.srt.cn/ubuntu/ precise-backports universe main multiverse restricteddeb-src http://ubuntu.srt.cn/ubuntu/ precise-backports universe main multiverse restricteddeb-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 multiversedeb http://mirror.lupaworld.com/ubuntu/archive/ precise-security main restricted universe multiversedeb http://mirror.lupaworld.com/ubuntu/archive/ precise-updates main restricted universe multiversedeb http://mirror.lupaworld.com/ubuntu/archive/ precise-backports main restricted universe multiversedeb http://mirror.lupaworld.com/ubuntu/ubuntu-cn/ precise main restricted universe multiverse

#ubuntu.cn99.com源（推薦）:deb http://ubuntu.cn99.com/ubuntu/ precise main restricted universe multiversedeb http://ubuntu.cn99.com/ubuntu/ precise-updates main restricted universe multiversedeb http://ubuntu.cn99.com/ubuntu/ precise-security main restricted universe multiversedeb http://ubuntu.cn99.com/ubuntu/ precise-backports main restricted universe multiversedeb http://ubuntu.cn99.com/ubuntu-cn/ precise main restricted universe multiverse

#電子科技大學 deb http://ubuntu.uestc.edu.cn/ubuntu/ precise main restricted universe multiversedeb http://ubuntu.uestc.edu.cn/ubuntu/ precise-backports main restricted universe multiversedeb http://ubuntu.uestc.edu.cn/ubuntu/ precise-proposed main restricted universe multiversedeb http://ubuntu.uestc.edu.cn/ubuntu/ precise-security main restricted universe multiversedeb http://ubuntu.uestc.edu.cn/ubuntu/ precise-updates main restricted universe multiversedeb-src http://ubuntu.uestc.edu.cn/ubuntu/ precise main restricted universe multiversedeb-src http://ubuntu.uestc.edu.cn/ubuntu/ precise-backports main restricted universe multiversedeb-src http://ubuntu.uestc.edu.cn/ubuntu/ precise-proposed main restricted universe multiversedeb-src http://ubuntu.uestc.edu.cn/ubuntu/ precise-security main restricted universe multiversedeb-src http://ubuntu.uestc.edu.cn/ubuntu/ precise-updates main restricted universe multiverse

#北京理工大學 deb http://mirror.bjtu.edu.cn/ubuntu/ precise main multiverse restricted universedeb http://mirror.bjtu.edu.cn/ubuntu/ precise-backports main multiverse restricted universedeb http://mirror.bjtu.edu.cn/ubuntu/ precise-proposed main multiverse restricted universedeb http://mirror.bjtu.edu.cn/ubuntu/ precise-security main multiverse restricted universedeb http://mirror.bjtu.edu.cn/ubuntu/ precise-updates main multiverse restricted universedeb-src http://mirror.bjtu.edu.cn/ubuntu/ precise main multiverse restricted universedeb-src http://mirror.bjtu.edu.cn/ubuntu/ precise-backports main multiverse restricted universedeb-src http://mirror.bjtu.edu.cn/ubuntu/ precise-proposed main multiverse restricted universedeb-src http://mirror.bjtu.edu.cn/ubuntu/ precise-security main multiverse restricted universedeb-src http://mirror.bjtu.edu.cn/ubuntu/ precise-updates main multiverse restricted universe

#上海交通大學 deb http://ftp.sjtu.edu.cn/ubuntu/ precise main multiverse restricted universe deb http://ftp.sjtu.edu.cn/ubuntu/ precise-backports main multiverse restricted universedeb http://ftp.sjtu.edu.cn/ubuntu/ precise-proposed main multiverse restricted universedeb http://ftp.sjtu.edu.cn/ubuntu/ precise-security main multiverse restricted universedeb http://ftp.sjtu.edu.cn/ubuntu/ precise-updates main multiverse restricted universedeb http://ftp.sjtu.edu.cn/ubuntu-cn/ precise main multiverse restricted universedeb-src http://ftp.sjtu.edu.cn/ubuntu/ precise main multiverse restricted universedeb-src http://ftp.sjtu.edu.cn/ubuntu/ precise-backports main multiverse restricted universedeb-src http://ftp.sjtu.edu.cn/ubuntu/ precise-proposed main multiverse restricted universedeb-src http://ftp.sjtu.edu.cn/ubuntu/ precise-security main multiverse restricted universedeb-src http://ftp.sjtu.edu.cn/ubuntu/ precise-updates main multiverse restricted universe

#蘭州大學 deb ftp://mirror.lzu.edu.cn/ubuntu/ precise main multiverse restricted universe deb ftp://mirror.lzu.edu.cn/ubuntu/ precise-backports main multiverse restricted universedeb ftp://mirror.lzu.edu.cn/ubuntu/ precise-proposed main multiverse restricted universedeb ftp://mirror.lzu.edu.cn/ubuntu/ precise-security main multiverse restricted universedeb ftp://mirror.lzu.edu.cn/ubuntu/ precise-updates main multiverse restricted universedeb ftp://mirror.lzu.edu.cn/ubuntu-cn/ precise main multiverse restricted universe