Background　Dexmedetomidine(Dex) is a highly selective α2 adrenoreceptor agonist. Increasing evidences show that Dex not only has a positive effect on the protection of vital organs, like heart, brain and liver, but also plays critical roles in septic shock resuscitation, controlled hypotension and alcohol withdraw.　Objective　To review the pharmacological effects of Dex, thus to provide scientific basic for its clinical use.　Content　The relative published articles were collected from PubMed, Ovid Medline and Springer. Present analysis mainly focused on the effects of Dex on organ protection, septic shock resuscitation, alcohol withdraw and controlled hypotension.　Trend　The effects of Dex mentioned above and its mechanism will become a new hotpots problem．