Abstract: Objective To investigate endothelial damage/dysfunction in patients of type 2 diabetes mellitus complicated with hypertension.MethodsPlasma fast blood glucose, triglyceride, cholesterol, thromodulin, von Willebrand factor and nitric oxide as well as SBP and DBP were determined in 32 normal controls, 35 patients with type 2 diabetes mellitus and 31 with type 2 diabetes mellitus complicated with hypertension.ResultsSBP, DBP, plasma fast blood glucose, triglyceride, cholesterol, thromodulin and von Willebrand factor were greater in patients with type 2 diabetes mellitus complicated with hypertension （P＜0.01 or P＜0.05） while the level of nitric oxide was decreased （P＜0.01） as compared with simple type2 diatetes mellitus and normal controls. Triglyceride, cholesterol, thromodulin and von willebrand factor were increased in patients with simple type 2 DM （P＜0.01 or P＜0.05） . The level of plasma nitric oxide was correlated negatively with SBP, DBP, thromodulin and von Willebrand factor （r=-0.43, r=-0.40, r=-0.42, r=-0.47, respectively, P＜0.01） in patients with type 2 DM. The level of von Willebrand factor was correlated positively with SBP, DBP, triglyceride and cholesterol （r=0.33, r=0.29, r=0.25, r=0.26, respectively, P＜0.01 or P＜0.05）. The level of thromodulin was correlated positively with SBP, DBP, triglyceride, cholesterol and von Willebrand factor （r=0.35, r=0.32, r=0.26, r=0.27, r=0.40, respectively, P＜0.01 or P＜0.05）.ConclusionThe endothelial damage/dysfunction was aggravated in patients with type 2 diabetes mellitus when complicated with hypertension. The development of hypertension in patients with type 2 diabetes mellitus may be close related to endothelial damage/dysfunction.