Preoyerative sedation of children is a difficult problem of great importance, for the psychic trauma comsequent to anticipation of surgery may be as great a hazard to the patient as his original disease. Until now, a number of sedatives have been used commonly for adequate sedation of pediatric patients, but, no method has been universally accepted. At our hospital fifty pediatric patients receiving general anesthesia for minor elective surgery were studied to evaluate the effect of ketamine hydrochloride as a preanesthetic agent. The results were as follows: 1) The onset of drag action was about, about 5min. 2) The induction of anesthesia and maintenances of operation was smooth, because a sedative effect was obtained without cardiovascular and respiratory depression. 3) With a small dosage of ketamine(2mg/kg), patients were free from apprehension. So, perioperative psychic trauma was preventible. 4) The two excitable patients were anesthetized by intravenous anesthetics with ease. 5) Mild complications, accurred but they were not significant.