Abstract:Traditional Chinese medicine (TCM) experienced a gradual course in recognition of the toxicity of Cinnabaris from "nontoxic" to "toxic". The ancient doctors of TCM understood both the toxic property and the regularity of increasing toxicity of Cinnabaris. In long-term clinical practice they developed the methods of detoxification guiding the safe use of Cinnabaris. The toxicity of Cinnabaris is produced by mercury existed in it. Improper administration leading to an acute absorbtion or chronic accumulation was the main cause of clinical adverse effects. Kidney was the main poisoning target organ. On the other hand, improperly combinative application of Cinnabaris with other drugs of TCM or western medicine could increase the toxicity. Therefore, the crucial approach to avoid the poisoning is to use Cinnabaris properly.