Abstract: Aim To observe the effects of supplement of folic acid, vitamin B 6 and vitamin B 12 on the hyperhomocysteinemia and arteriosclerosis induced by ingestion of excessive methionine（Met）. Methods Thirty male New Zealand White rabbits were divided into three group:Control group（CG）, Met group（MG）, and Met+vitamins B group（VG）.\ The latter two groups were fed with a normal diet supplemented with 0 5% Met and a 0 5% Met diet while the VG group supplemented with Vitamin B（2.5 mg folic acid,10 mg vitamin B 6, 200 μg vitamin B 12 daily） for six months. The levels of plasma homocysteine（Hcy）, thromboxane B 2（TXB 2）, 6 k prostaglandin（6 k PGF 1α ） and serum folic acid were measured.The histological changes of aortas were examined by light microscopy. Results After experiment, the level of serum folic acid in VG was higher than those in MG and CG and preexperiment. In CG,the levels of plasma Hcy at 2 h and 7 h after the cessation of diet were lower than those in MG, and the levels of plasma TXB 2 and TXB 2/6\|k\|PGF 1α in MG were increased.\ The severity of arterial lesions in VG was significantly milder than that in MG, and the levels of plasma TXB\-2 in VG were lower than those in MG.\ There were no significant difference in the levels of plasma 6\|K\|PGF 1α among three groups. Conculsion Supplement of folic acid, Vitamin B 6 and Vitamin B 12 may reduce plasma Hcy level and atherosclerostic lesions by intake of excessive methionine.