There is growing evidence that soy isoflavones play beneficial role in the prevention of cardiovascular disease. However, current data are not sufficient to determine the effective dose of isoflavone on improving plasma lipid profiles and total antioxidant capacity in Korean menopausal women. In the present study, 24 perimenopausal and 23 postmenopausal women were divided into 3 groups and were given soy isoflavone supplements of 100, 150, 200mg/day for 12weeks. Blood samples were taken before and after 6, 12weeks of soy isoflavone supplementation for analysis of total cholesterol, LDL cholesterol, HDL cholesterol, triglyceride and total antioxidant status(TAS). In the perimenopausal women, serum total cholesterol level decreased significantly in all three groups after 12weeks of isoflavone supplementation(p< 0.05). However, serum LDL cholesterol level significantly lowered only in 150 and 200mg groups, and serum triglyceride level decreased significantly in 200mg group(p<0.05). In the postmenopausal women, the 150mg isoflavone supplementation group demonstrated significant effects on lowering serum total cholesterol, LDL cholesterol levels and raising HDL cholesterol level after 12weeks of isoflavone supplementation(p<0.05). Two hundred mg isoflavone supplementation group had a significantly higher TAS than other groups in both perimenopausal and postmenopausal women. (Korean J Nutrition 34(3) : 322∼329, 2001)