Ubuntu中软件更新的源服务器地址存储再/etc/apt/soures.list中。文件中的内容如下： deb http://archive.ubuntu.com/ubuntu/ trusty main restricted universe multiverse deb http://archive.ubuntu.com/ubuntu/ trusty-security main restricted universe multiverse deb http://archive.ubuntu.com/ubuntu/ trusty-updates main restricted universe multiverse deb http://archive.ubuntu.com/ubuntu/ trusty-proposed main restricted universe multiverse deb http://archive.ubuntu.com/ubuntu/ trusty-backports main restricted universe multiverse deb-src http://archive.ubuntu.com/ubuntu/ trusty main restricted universe multiverse deb-src http://archive.ubuntu.com/ubuntu/ trusty-security main restricted universe multiverse deb-src http://archive.ubuntu.com/ubuntu/ trusty-updates main restricted universe multiverse deb-src http://archive.ubuntu.com/ubuntu/ trusty-proposed main restricted universe multiverse deb-src http://archive.ubuntu.com/ubuntu/ trusty-backports main restricted universe multiverse 上面是ubuntu官方的软件源。具体含义如下，
每一行的开头是deb和deb-src，表示直接通过.deb文件或者源文件的方式来进行安装; 第二字段，即deb和deb-src字段后是一段URL，这是软件源的地址 第三字段，即URL后的字段，是再URL路径中的dists目录下对应的文件夹，如图所示 第四～七字段都是第三字段对应的目录下的子目录
但是由于ubuntu的官方软件源下载速度慢而且有些第三方软件的安装包过于陈旧，已不能满足用户的需求。因此需要添加第三方软件更新源。本文以163的软件源为例讲述更新软件源的方法。
在网上能够很方便的查到163的ubuntu的软件源的方法，sudo gedit /etc/apt/source.list，再打开的文件中添加如下内容： deb http://mirrors.163.com/ubuntu/ raring main restricted universe multiverse deb http://mirrors.163.com/ubuntu/ raring-security main restricted universe multiverse deb http://mirrors.163.com/ubuntu/ raring-updates main restricted universe multiverse deb http://mirrors.163.com/ubuntu/ raring-proposed main restricted universe multiverse deb http://mirrors.163.com/ubuntu/ raring-backports main restricted universe multiverse deb-src http://mirrors.163.com/ubuntu/ raring main restricted universe multiverse deb-src http://mirrors.163.com/ubuntu/ raring-security main restricted universe multiverse deb-src http://mirrors.163.com/ubuntu/ raring-updates main restricted universe multiverse deb-src http://mirrors.163.com/ubuntu/ raring-proposed main restricted universe multiverse deb-src http://mirrors.163.com/ubuntu/ raring-backports main restricted universe multiverse 保存退出后运行命令：sudo apt-get update。 但是，这样修改后会在更新软件时会出现404 not found的错误，这是由于对于ubuntu各个版本的软件位置是不一样的，因此，需要根据ubuntu的版本号来选择对应的软件源路径。
ubuntu各版本的名称如下
版本号代号发布时间15.04Vivid Vervet2015/414.10Utopic Unicorn2014/10/2314.04 LTSTrusty Tahr2014/04/1813.10Saucy Salamander2013/10/1713.04Raring Ringtail2013/04/2512.10Quantal Quetzal2012/10/1812.04 LTSPrecise Pangolin2012/04/2611.10Oneiric Ocelot2011/10/13由于我的ubuntu版本是14.04所以需要将上面的内容修改为： deb http://tel.mirrors.163.com/ubuntu/ trusty main restricted universe multiverse deb http://tel.mirrors.163.com/ubuntu/ trusty-security main restricted universe multiverse deb http://tel.mirrors.163.com/ubuntu/ trusty-updates main restricted universe multiverse deb http://tel.mirrors.163.com/ubuntu/ trusty-proposed main restricted universe multiverse deb http://tel.mirrors.163.com/ubuntu/ trusty-backports main restricted universe multiverse deb-src http://tel.mirrors.163.com/ubuntu/ trusty main restricted universe multiverse deb-src http://tel.mirrors.163.com/ubuntu/ trusty-security main restricted universe multiverse deb-src http://tel.mirrors.163.com/ubuntu/ trusty-updates main restricted universe multiverse deb-src http://tel.mirrors.163.com/ubuntu/ trusty-proposed main restricted universe multiverse deb-src http://tel.mirrors.163.com/ubuntu/ trusty-backports main restricted universe multiverse 然后再次保存，sudo apt-get update
参考资料： [1]http://www.cnblogs.com/jiangz/p/4076811.html?utm_source=tuicool&utm_medium=referral [2]http://www.cnblogs.com/tsingke/p/3832765.html [3]http://baike.baidu.com/link?url=35tSbrwOYsEaxPsGPV3PeM16UibDD8ot1lUar0cOKvsJCc1rd7NgVMxZzDPet17QQq2rrOPhzW4Ceccsi8RVua
