Chinese Language Packs. note: The TinyMCE works in English, because I can't set the language code to zh-CN.
click this link for detail.
http://processwire.com/talk/topic/4803-i-want-translate-pw-to-chinese-and-need-support/
you can download this pack from github too. https://github.com/liyiwu/Chinese-ProcessWire
update:
cd wire
grep -Rl '[>_][_nx](' * | uniq
I find 90 files, and translate all of them that is translatable.
Hope this can help others.
Chinese-ProcessWire.zip