My suggestion is... since, undoubtedly, others have run into the same problem as you have before, you should search around on Google for people that have had issues with chinese characters in MySQL databases.
The biggest issue here is you've got a problem that could be occurring on one of three different depedencies. It could be a problem with how you're storing it (MySQL), what datatype you're throwing it into (PHP), or how you're displaying it (XHTML).
I'd suggest, if you can't find out the solution by Googling for other people having the same problem, you should first eliminate the layers the problem could be sitting on. From PHP, output it to a server-side text file (with the proper encoding format) instead of HTML. If that does not work, you know the problem is in either PHP or MySQL. Keep working your way up until you have excluded the problematic area. Then, if for instance, the problem happens to be with MySQL, search the documentation for support with storing Chinese encoded characters.
Cheers,
- Sane