1、備份

sudo cp /etc/apt/source.list /etc/apt/source.list.bak

2、打開/etc/apt/source.list，並刪除所有內容

sudo gedit /etc/apt/source.list 

3、復制以下內容到該文件，保存。

阿裏雲源：

    # deb cdrom:[Ubuntu 16.04 LTS _Xenial Xerus_ - Release amd64 (20160420.1)]/ xenial main restricted  
    deb-src http://archive.ubuntu.com/ubuntu xenial main restricted #Added by software-properties  
 

    deb http://mirrors.aliyun.com/ubuntu/ xenial main restricted  
    deb-src http://mirrors.aliyun.com/ubuntu/ xenial main restricted multiverse universe #Added by software-properties  
    deb http://mirrors.aliyun.com/ubuntu/ xenial-updates main restricted  
    deb-src http://mirrors.aliyun.com/ubuntu/ xenial-updates main restricted multiverse universe #Added by software-properties  
 

    deb http://mirrors.aliyun.com/ubuntu/ xenial universe  
    deb http://mirrors.aliyun.com/ubuntu/ xenial-updates universe  
    deb http://mirrors.aliyun.com/ubuntu/ xenial multiverse  
    deb http://mirrors.aliyun.com/ubuntu/ xenial-updates multiverse  
    deb http://mirrors.aliyun.com/ubuntu/ xenial-backports main restricted universe multiverse  
 

    deb-src http://mirrors.aliyun.com/ubuntu/ xenial-backports main restricted universe multiverse #Added by software-properties  
    deb http://archive.canonical.com/ubuntu xenial partner  
    deb-src http://archive.canonical.com/ubuntu xenial partner  
    deb http://mirrors.aliyun.com/ubuntu/ xenial-security main restricted  
    deb-src http://mirrors.aliyun.com/ubuntu/ xenial-security main restricted multiverse universe #Added by software-properties  
    deb http://mirrors.aliyun.com/ubuntu/ xenial-security universe  
    deb http://mirrors.aliyun.com/ubuntu/ xenial-security multiverse  

4、更新源

sudo apt-get update 

完成。

ubuntu16.04 更換源