OK firstly Im a bit of a newb with Linux, and can only advise you based on my distribution of Linux (Ubuntu), but it is easy with Ubuntu so it should be easy enough to transfer the instructions over to your distribution.
Navigate to System --> Administration --> Software Sources
On my distribution System is on the menu at the top of the screen!!
Select all the tick boxes ensuring that you are connecting to all available servers, if you include third party servers too although they are not guranteed to be supported 9 times out of 10 they come in handy so just select all of them .
Now that you have your Linux Box looking for all source download sites for available software select Close.
Navigate to System --> Administration --> Language Support
Follow the On-Screen instructions to update the content list. Once updated there will be a comprehensive list of available Languages to select from. And Chinese is there in alphabetical order.
I hope this helps