MKV file is not the regular video and audio compression format,it is an open source container format.We can use VLC Media Player to play mkv files in ubuntu,we just need to install VLC in ubuntu to do it.

To install VLC in ubuntu ,you just need to use the follow 2 commands:

% sudo apt-get update
% sudo apt-get install vlc vlc-plugin-esd mozilla-plugin-vlc

Tips:Of course you also can use Synaptic Package Manager to install VLC for your Ubuntu

After the VLC been installed,you can find it in your menu:


Now you can use VLC to paly mkv files in ubuntu: