In order to compare the effect of megadoses of vitamin B6 and C on serum lipids and atheroscleosis, 25 New Zealand strain rabbits (male) fed high cholesterol diet every day were divided into four groups.Group A as control, received only cholesterol diet. 125mg.kg-1.d-1 of vitamin B6 was given to group B, 500mg.kg-1.d-1 of vitamin C to group C, and 125mg.kg-1.d-1 vitamin B6+500 mg.kg-1.d-1 vitamin C to group D, all by oral administration. Fasting serum was sampled at 2-week intervals during a 10-week experimental period. After 10 weeks, killed all the rab- bits, check their urethrae and determined the vitamin C content of the adrenal glands. The aorta was examined by measuring the size of plaques OR aorta wall and investigated pathologically.The results were (1) The body weight increased in every group gave no remarkable difference. (2) Serum total-cholesterol (TC) of group B was apparently lower than group A at 8th week (P