Abstract: Realgar is a common component of classical Chinese medicine preparation， which has attracted much attention due to high content of arsenic sulfide. This reviewed the research on the species， toxicity and molecular mechanism of arsenic in recent years. The clinical adverse effects of realgar-containing preparations and the safety of realgar on chronic exposure to experimental animals were analyzed. In particular， the classic Chinese medicine Liushen Wan compatibility reduced realgar-induced toxicity. That illustrated that the Chinese medicine preparations containing realgar clinically used at low dose and reasonable medication time， have certain drug safety.