12,688 cases of operative patients who received operation at kyungpook National University Hospital from Jul. 1977 to Dec. 1981 were analyzed according to each year, each surgical department, anesthetic technique, and the ratio of medical insurance patients after enforcement of medical insurance system. 1) Total operative patients were 12,688 cases including general patients 7,084 cases(54%) insurance patients 3,934 cases(31%), public assistance recipient 906 cases(7%), and industrial accident patients 764 cases(6%). 2) Total patients and insurance patients increased annually, while general patients decreased gradually. 3) Though regional and general anesthetic cases of general patients, decreased annually, those of insurance patients increased year by year. 4) Among the surgical department, the highest rate wwas neurosurgery 850 cases(73%) in general patients, E.N.T. 354 cases(54%) in insurance patinets, chest surgery 94 cases(17%) in public assistance recipient, and orthopedic surgery 350 cases(17%) in industrial accident patients. 5) E.N.T. department showed largest increase in insurance patients among surgical sections.