A partial list of
prohibited subjects: "
wronged spirits and violent ghosts, monsters, demons, and other inhuman portrayals, strange and supernatural storytelling for the sole purpose of seeking terror and horror." The Chinese government's stated goal is to "control and cleanse the negative effect these items have on society, and to prevent horror, violent, cruel publications from entering the market through official channels and to protect adolescents' psychological health."
EDIT: I see
_thespookhouse_ picked up on this as well.