This study was performed to investigate the serum lipid levels and fatty acid composition in middle-aged men and the influence of cardiovscular risk factors on them. Data for dietary intake, anthropometry , blood pressure, and general environmental factors were obtained and their relationship to serum lipid levels and fatty acid composition were analyzed in 303 healthy male subjects with a mean age of 43.8$pm$6.4 years from June 1 to 22 , 1995. The prevalence of obesity was 26.7% by BMI and 11.2% by WHR criteria . The percentage of hypertensive subjects were 13.5% and 22.4% by systolic and diastolic blood pressure, respectively. Retinol, calcium , and roboflavin intakes were lower than the RDA for Koreans. The ratio of carbohydrate intake to total calories of the subjects was 70%. Ratios of P/M and n-6/n-3 were 1.02/1.05/1.00 and 11.1/1, respectively. The percentage of subjects who had serum TG, TC, LDL-C leves beyond the normal range were 19.5% , 13.5% and 8.6% respectively. Palmitic comprised 26.4% of serum total fatty acids, linoleic acid 19.4% and oleic acid 16.4. The waist circumference and ration of carbohydrate intake were related positively to TG level. Serum cholesterol level had positive relations with waist circumference, DBP, sugar intake, and income. There were positive relationships between SFA and bone fishes and vegetable oil intakes, MUFA and DBP while a negative a negative relationship was observed between PUFA and animal fat intake. Serum n-6 fatty acid was related negatively to carbohydrate intake and hot taste preference. N-3 fatty acid was related positively to fish intake and negatively to egg intake. These results suggest that to maintain adequate serum lipid levels and fatty acid composition, sugar, animal fat, and carbohydrate intakes have to be reduced, while consumption of vegetable oil and fish must be increased. It is also essential to control abdominal fat accumulation and blood pressure.