Abstract: Objective: To study the clinical significance of telmisartan treatment on insulin sensitivity and endothelial function in elderly diabetic patients with hypertension.Methods:Sixty-eight elderly diabetic patients with hypertension were randomly selected in our hospital,and divided into two groups,the patents in study group (34 cases) were required regular quantitative taking alternate telmisartan 40 mg per day treatment; the patients in control group(34 cases) taking amlodipine 2.5 mg per day,the insulin sensitivity including fasting blood glucose(FBG) level,fasting insulin(FINS),insulin resistance index(IRI) and vascular endothelial function including the changes of endothelin-1(ET-1) and nitric oxide(NO) were observed.Results:Compared with the control group,FBG,FINS,IRI in the study group were decreased after telmisartan treatment (P0.01) ; compared with the control group,there had statistical differences of ET-1 and NO in the study group after telmisartan treatment(P0.01 and P0.05).Conclusions:Telmisartan can effectively improve insulin sensitivity and endothelial function in elderly diabetic patients with hypertension.