Abstract: Aim To investigate the effect of different doses of captopril on atherosclerosis in rabbits. Methods 53 male Japanese white rabbits were randomly divided into control group, cholesterol group and captopril group of high , middle , low dose. The change of serum lipid concentrations and the histopathological changes of aorta were studied. The positive expression of pro oncogene c myc and c fos mRNA was also studied with in situ reverse transcription PCR （ISRT PCR）. Results （1）Serum lipid levels in captopril group had no significant change compared with cholesterol group. The ratio of aorta plaque areas in high dose captopril group was significantly lower than that of the cholesterol group （ P ＜0 01） with the foam cells being remarkably decreased. No significant difference was observed between of low dose captopril and cholesterol group. （2） Positive expression rate of pro oncogene c myc and c fos mRNA was significantly higher in cholesterol group than in the control group. The rate of positive expression was remarkably lower in the high dose captopril group than in the cholesterol group （ P ＜0 05）. No significant difference was found between groups in middle,low dose groups or in the cholesterol group. Conclusions The study had suggested that inhibits the formation of aorta plaque and prevent atherosclerotic development,a higher dose of captopril is likely necessary.