Cinnabar has been an important traditional Chinese medicine as a sedative and soporific agent for more than 2000 years. It is a naturally occurring mercuric sulfide and containing more than 96% mercuric sulfide (HgS). There are about 10% -30% Chinese patent medicines containing cinnabar according to the Pharmacopoeia of China (2005). It's hard to deny that cinnabar has therapeutic effect in clinic practice. However, cinnabar's extraordinary high containing mercury makes people hesitate to use. Furthermore, the abuse of cinnabar, which caused intoxication cases, has been reported occasionally. The safety and toxicity of cinnabar has been debated for centuries. The exact mechanism of cinnabar is still largely unknown. The present review focused on researches about cinnabar's mechanisms of pharmacological and toxicological effects since 2000.