Mine does not do that.
I'm going to make a few guesses... let me know how close I get...
1. You're playing a modded MC game.
2. You haven't tried playing in vanilla to see if that too has this problem.
3. If you drag all mods from the /mods folder to your desktop and play your current version it also will not change to chinese.
If the above are all yes, add the mods back in a few at a time until you find the cause of your problem. Once you find the mod causing this post please report it to that mod's forum. Think about the next guy.