You can use Chinese if and only if you provide a full translation to English, Spanish, or French and provide an easy way to switch between languages without needing to register. You cannot just throw in a Google Translate widget.
If you do not provide a full direct translation, this falls under the Zero Tolerance Policy.
If you are wondering how to make pages in Chinese show in the browser properly: make sure all files are saved in UTF-8 and if you have and databases, make sure they are all in utf-8_general as well. The html should have a meta tag such as this: