Background Dexmedetomidine(DEX) is a novel and highly selective α2-adrenoceptor agonist. The agonist produces sedation，analgesic, anxiolytic effect, and without relevant respiratory depression. At the same time, dexmedetomidine can maintain hemodynamic stability, and decrease the opioid consumption and its side effects. Many studies revealed that dexmedetomidine can be used in the adult widely and safely, much more attention would be paid to whether it can be used in children safety. Objective To summarize the efficacy and safety of dexmedetomidine used in puerile cardiosurgery. Content To review the effect of dexmedetomidine on the hemodymamics, respiratory and recovery time as well as electrocardiogram in puerile cardiosurgery; besides, its application in puerile intensive care unit is also approached. Trend The experience of dexmedetomidine used in pediatric anesthesia is relatively deficiency. Therefor, the action mechanism and safety dosage of DEX need further study for the better clinical application in children.