www.stc2002.com shanghai tianma circuit. 2km long, twisty but you can hit about 120-130kph in a reasonable 1600cc car, check
www.fightingtorque.com for video.
organised days, plus on most days you can pay 100rmb for 25 mins free practising. also has off road course.
http://www.goldenport.com.cn/ - beijing area. never been there. similar size to tianma. also has off road course.
www.zic.com.cn zhuhai circuit close to guangzhou. never been there, it's quite a big circuit, theoretically F1 standard.
Shanghai F1 circuit - may have some track days this year but not announced yet.
Also there is karting in the big cities , internet search should show it up.
If you can read chinese, try
www.chinahotcar.com and go the the FB section to see what is going on.
cheers,
FT