Objective To observe the effect of methionine-induced hyperhomocysteinamia on methylation status of Bcl-2 and Bax in aorta of rats.Methods Twenty-our healthy six-week-old Wistar male rats, weighting (150±10) g were randomly divided into control group and Hhcy group (n=12 each).The contol was given AIN-93G food.The Hhcy was received AIN-93G and methionine(1 ·kg· g-1·d-1· , orally); twenty weeks later, rats were sacrificed.the homocysteine in plasma was measured with automatic biochemistry analyzer.Msp (methylation specific PCR) and net touchdown were used to detect methylation status of Bcl-2 and Bax.