Objective To explore the effect of NaHS(H2S donor)on the pathogenesis of atherosclerosis in rabits.Methods Forty male new Zealand white rabits were divided into normal group,modern group,hyperlipid diet+sodium hydrosulfide(NaHS group),hyperlipid diet+PPG group with 10 rabits in each group.The serum levels of total cholesterol,triglyeride,low density lipoprotein and high density lipoprotein were examined.The methylene blue method was used to determine the content of H2S,the colorimetric method was used to detect the content of SOD and the activity of MDA;Histological changes in aoritic root were studied by H-E staining and histomorphometric analysis.Results Compared with the modern group,the changes of serum lipids in the NaHS group were not significant;the serum of H2S content and SOD activity increased significantly,the MDA content decreased significantly,pathomorphology indicated that intima and media(I+M)became thinned,the thickness ratio of intima/middle and the area of intima to media were decreased(P<0.05).Compared with the NaHS group,the H2S content and SOD activity in the PPG group decreased significantly,and the MDA content increased significantly;HE staining showed the thickness ratio of intima/middle lay-er,I+M,the area of ratio of intima/middle layer significantly were increased(P<0.05).Conclusions Exogenous hy-drogen sulfide can postpone the proceeding of atherosclerosis by changing the oxidative stress state and inhibited the for-mation of atherosclerosis.