Aim To investigate the effects of losartan, captopril and combined administration on the atherosclerotic renal vascular disease, so as to discover the anti atherosclerotic mechanism of these two drugs. Methods Serum nitric oxide (NO), tissue plasminogen activator(t PA), inhibitor of t PA and angiotensin converting enzyme were detected by chemical method; endothelin (ET) and angiotnesin Ⅱ were detected by radioimmuno assay. The apoptosis of vascular smooth muscle cells (VSMC) was determined by cytometry technique; Expression of CD68 protein were detected by immunohistochemical method; the expression levels of MMP1 and TIMP1 mRNA were examined by reverse transcription polymerase chain reaction. Results Losartan and captopril had no influence on serum lipid, creatine and BUN. Losartan alone and combined use with captopril could lower blood pressure significantly. The degree of renal and aortic atherosclerosis had good correlation. Compared with cholesterol diet group, losartan and combined drug administration group had smaller renal intimal area ratio (p<0.05), lower cholesterol contents in the renal atherosclerotic plaque (p<0.05), higher apoptosis percentage of VSMC (p<0.01) and lower levels of the expressions of CD68 protein (p<0.05) and MMP1 mRNA. Losartan may also elevate serum content of t PA(p<0.05). Conclusions Losartan and captopril can influence the pathogenesis of renal atherosclerosis by lowering blood pressure, enhancing apoptosis of VSMC, improving endothelial function, increasing fibrolysic function and stabilizing atherosclerotic plaque.