Background Dexmedetomidine（Dex） is a novel selective α2 receptor agonist that produces sedation and analgesia. Another advantage of dex is the lack of significant respiratory depression. Dex has caused extensive concern from doctors.　Objective　To present the pharmacodynamics and pharmacology of dex and to discuss the application of dex as an appropriate sedative and analgesic for patients during perioperative period.　Content　Dex has been used in various clinical fields， such as premedicate， intraoperative anesthesia adjuvant drugs and postoperative analgesia.　Trend　With more depth studies， dex， as an anesthesia adjuvant drugs， will be widely used in clinical work.