Objective To compare the effects of ketamine combined with butorphanol intravenous anesthesia with ketamine separately for pediatric day surgery. Methods In this double-blind trial, 200 pediatric patients (ASA physical status1 or 2, 1–6 years old) undergoing inguinal hernia repair or circumcisions under intravenous anesthesia were randomly allocated into two groups. Intravenous anesthesia was induced with 2 mg/kg ketamine combined with 2ml saline (group KS, n = 100) or 2mg/kg ketamine combined with 30μg/kg butorphanol in the volume of 2ml respectively (group KB, n = 100). Repeat doses of ketamine 1 mg/kg were administered when the patients had motor respsones. Total dosage of ketamine, variation of circulation and breath, awaken time after operation were observed. Agitation was assessed with sedative score and pain with CHEOPS score. The patients’ parents were interviewed 24 h after surgery, and the adverse events were recorded. Results Group KB showed less consumption of ketamine(42.2±12.9mg vs 75.0±25.3mg P＜0. 05). Furthermore, the mean postoperative CHEOPS score and sedative score in the group KB were significantly lower than in the group KS( P＜0. 05). Awaken time were statistically longer in the group KS( P＜0. 05), but the time spent in the PACU were similar in both groups. There was no significantly airway or hemodynamic effects observed in both groups. Conclusion Ketamine combined with butorphanol for pediatric day surgery is an ideal anesthesia and it has such advantage as safe, low dosage of keatmine to eliminate the adverse effect, providing a more comprehensive sedative and analgesic effects to reduced emergence agitation and postoperative pain in pediatric day surgery.