Objective：To investigate the effect of angiotensin Ⅱ receptor blocker on atherosclerosis aortic endothelial cells through treating atherosclerotic rats with ARB. Methods：Totally 30 Wistar rats were randomly divided into 3 groups： model group，experiment group and control group with 10 rats in each group. Atherosclerosis rat model was established in model group by feeding high fat diet. Valsartan intervention was added in experiment group. After eight weeks，nitric oxide（NO），endothelin（ET），cytochrome-c（Cyt-c） and plasma endothelial lipase（EL） levels of aortic endothelial cells were compared. Results：At the end of the experiment，HE stain－ing of model group showed obvious plaque formation with a large amount of lipid infiltration. Immunohistochemical staining of Cyc-c showed that the positive rate of apoptosis of endothelial cells were higher in model group（36.85±12.45） than in control group（0.81±0.11） and experimental group（13.85±6.41）（P=0.000）. The positive rate of apoptosis of smooth muscle cells was higher than in model group（9.65±2.62） than in control group（0.06±0.01）（P=0.000），but did not statistically different from that of experimental group （7.85±1.34）（P=0.058）. Total cholesterol（TC） and low-density lipoprotein cholesterol（LDL-C） levels in model group and experi－mental group were increased significantly，however，did not statistically different those in control group（P=0.000）. There was statisti－cally significant difference in TC and LDL-C between model group and experimental group（P=0.000，P=0.002）. There was statistically significant difference in ET-1，NO，EL between model group，experimental group and control group（P=0.000）. There was statistically significant difference in ET-1，NO，EL between model group and experimental group（P=0.017，0.008，0.000）. Conclusion：Valsarta can protect function of endothelial cells during cell injury period. For patients with early atherosclerosis，Valsarta could protect the integri－ty of cells，reduce the apoptosis，playing a significant role in the prevention and treatment of disease.