Aim To investigate the effect of simvastatin on endothelium dependent relaxing function, intima-media thickness (IMT) of carotid in elderly patients. Methods With high-resolution ultrasound, before and after simvastatin treatment, endothelium dependent relaxing function and IMT of carotid arteries were measured in 60 subjects: 20 with primary hypercholesterolemia, 20 with coronary heart disease and hypercholesterolemia and 20 controls. Results In elderly patients, IMT of carotid arteries was higher and flow-mediated dilatation was much reduced compared with that of control group. After therapy with simvastatin 20 mg/d for 3～4 months, total cholesterol, triglyceride, low density lipoprotein cholesterol(LDLC) and high density lipoprotein cholesterol(HDLC) were much reduced, and flow-mediated vasodilation was improved than before, though it was still lower than control group. There was no significant changes of IMT. Conclusions Endothelium dependent vasodilation was impaired in elderly hypercholesterolemia patients, whose IMT of carotid arteries was increased. Simvastatin improves impaired endotheliumdependent vasodilatation, but with little effect on increased IMT of carotid arteries.