Aim of investigation¡GThe purpose of the randomized, double blind study is to determine whether intravenous ketamine will reduce the frequency of emergence agitation and whether the timing of ketamine administration have any impact on the recovery profile of sevoflurane anesthesia, will also be investigated. Methods¡GWe study 223, under 12 years old, otherwise healthy children of ASA physical status I and II, who will undergo polio-related surgery. During the operation, the keta group (n =96) receive ketamine intravenously; and the Control group(n = 127) receive saline as control and ketamine will be administered only when the Agitation Scale¡Ù3 . In the recovery room, routine standard measurement every 30 minutes monitoring included blood pressure, SaO2, heart rate, respiratory rate, agitation scale, and pain scale. Postoperative pain was assessed using the Objective Pain Scale (OPS). Agitation level will be evaluated by using 5-point agitation scale. The data will be analyzed with SPSS. Results¡GThe use of ketamine on surgery pain management is effective within 30 min after surgery, buy not actually effective thereafter. Multiple factors affect the emergence of agitation. The satisfaction survey shows no difference whether using ketamine or not. Emergence agitation using ketamine expend highest cost. Conclusion¡GIt is considerable to further search a more costive and effective agent than ketamine after sevoflurane anesthesia.