Ban the entire China netblocks in .htaccess
order allow,deny
deny from ###.###.###.###
allow from all
You can find the China IP Blocks at
http://www.nirsoft.net/countryip/cn.htmlSo to get you started typing:
order allow,deny
deny from 1.0.32
deny from 1.0.33
deny from 1.0.34
deny from 1.0.35
deny from 1.0.36
deny from 1.0.37
deny from 1.0.38
deny from 1.0.39
deny from 1.0.40
deny from 1.0.41
deny from 1.0.42
allow from all
Keep going through all their netblocks.