Serum lipid levels and fatty acid composition of serum phospholipids(PL) were investigated in 24 healthy male subjects who consumed either corn oil(CO) rich in linoleic acid(LA), perilla oil(PO) rich in ${alpha}-linolenic$ acid($alpha-LNA$), or canola oil acid(OA) as a major. fat source for 5 weeks. The PO and the CNO groups showed significant(P<0.05) increases in serum high density lipoprotein-cholesterol(HDL-C) levels and in ratios of HDL-C/total cholesterol(TC) compared with initial values measured at the beginning of the study. Significantly(p<0.05) increased concentrations of serum triglycerides(TG) ware observed after 5 weeks of the CO-based diet compared with both its intial value and the concentration observed after 5 weeks with the PO-based diet. Fatty acid composition of serum PL reflected changes in dietary fatty acid composition and metabolism. Compared with the initial levels, significantly increased contents of eicosapentaenoic acid(EPA) and docosahexaenoic acid(DHA) were observed in serum PL of the PO group and significantly increased contents of ${alpha}-LNA$ and EPA were observed in the CNO group. Arachidonic acid(AA) content of serum PL did not change in the CO group during the study period, although, the increase in LA was significant(P<0.05). Compared with the CO-based diet, both the PO and the CNO-based diets seem to have beneficial effects on atherosclerosis by influencing the serum lipid profile and fatty acid composition of serum PL.