Sevoflurane is the volatile anesthetic agent of choice in pediatric surgery. Nevertheless, sevoflurane anesthesia had the high incidence of emergence delirium compared to halothane and isoflurane.Bortone L et al.reported isoflurane for maintenance decreased incidence of emergence agitation compared to sevoflurane in unpremedicated preschool children under elective subumbilical surgery (32% versus 52% respectively). Desflurane is the new volatile anesthetic agent which provides faster recovery compared to sevoflurane.Valley et al.reported no significant differences between sevoflurane or desflurane anesthesia in children in term of the serious airway complication such as laryngospasm or desaturation excepted the number of coughing episodes were more frequent in the desflurane compared to sevoflurane (36 versus 18).Mayer J et al. reported sevoflurane had severity of Pediatric Anesthesia Emergence Delirium (PAED) scale higher than desflurane in ear, nose, throat inpatient surgery in children (12(2-20) versus 6(0-15) respectively) with no reported of incidence of emergence agitation between those two. Therefore, the investigators would like to compare the incidence of emergence agitation, recovery profile and respiratory events between desflurane and sevoflurane anesthesia in pediatric ambulatory urologic surgery under general anesthesia and combined with regional anesthesia.