ln order to find the changing patterns of diabetic complications, we studied 6I2 NIDDM patients who were admitted to Seoul National University Hospitai from January 1989 to July 1990. The results svere as follows: 1) Diabetes was most prevalent in the 6th decade and 33.3% of the patients were diagonsed at their 5th decade 2) Average duration of diabetes was 10.1, years and the fequency of complications increased according to the duration of disease. An increase in prevalence of diaibetic complications was noted after 40 years of age 3) Diabetic neuropathy showed 61.3% as their frequency and in the patients with diabetic duration was less than 4 years, the frequency of neuropathy was 31. 5 % 4) Nonproliferative and proliferative retinopathy showed 35.0%, 27.6%, as their frequency respectively. 5) 16.3% of patients had prateinuria over 0.5 gm/day without azotemia and renal insuffienry was observed in 17.2% of patients. 6) Macrovasular compliications were faund in 11.4% of patients and the prevalence of cerebrovascuIar disease, ischemic heart disease were 5. 7 %, 5.2% resspectivly. Diabetic foot lesions had a frequency of 5.4% and foot gangrenes were found in 1.8% of patients. These results suggest that chronic diabetic complications are related to the duration of disease and the proportion of elderly patient show increasing tendency The higher prevalence of complications in whom who had diabetic duration was less than 4 years, necessitate the early detection and strict control of these complications.