Postoperative hypoxemia has been well known is adults but not in infants and children, although they are potentially more susceptible to airway closure and to disturbances in pulmonary gas exchange. We measured blood gas parameters of capillary blood in 30 cases of ASA physical status class l infants and children breathing room air, before and after general anesthesis for superficial surgical procedures. The blood samples were taken preoperatively, on arrival and 4~6 minutes later in the recovery room. The results are as follows: 1) The blood gas parameters on arrival in the recovery room showed significant change in pH nad PCO2(p<0.01) and increased PCO2(p<0.01) in comparison with preoperative gases. 2) The blood gas parameters checked at 4~6 minutes later in the recovery room showed insignificant differences from preoperative values of PO2 and SO2, but significantly increased PCO2 and decreased pH(p<0.01). 3) As a results of this study, it is suggested that for the safe management of patients, supplementary oxygen be provided for at least 10 minutes in the early recovery period to all pediatric patients.