Two thound and eight hundred and ninety cases of diabetes mellitus who were admitted to 7 hospitals in Korea from March 1952 to August 1975 were analysed and the following results were obtained. 1.during the same period, the total inpatients were 342,948, giving an overall incidence of the diabetes mellitus 0.84%. The male patients dominated the female by the ratio of 1.9 to 1. The peak. Incidence occurred in 6th decade. 2. Prabable precipitating factor of diabetes mellitus were obesity(19,3%) heredity(9.0%) and infection (5. 2%) in order of frequency. The precipitatinig factors could not be elicted in 61.5% . Common symptons of the onset of the. Diabetes mellitus were thirst (43.02%) polyuria (37.18%) and weakness(32.86%) 4.The mild fastinng hyperglycemia'(less than 150mg%) were seen in 38.3% of diabetics. 5. The hypercholesterolemla (over 200 mg%) were seen in 47.6% of diabetics. 6. The associated complications.of the diabetes mellitus were infection (30.47%) , neuropathy (28.88%) and hypertension (22.67%) The diabetic coma encounatered in 1.92%.