Aim To study the relationship between brachial-ankle pulse wave velocity(BaPWV) and serum malonyldialdehyde(MDA),superoxide dismutase(SOD) and nitric oxide(NO) in patients with hypertension co-existed with type 2 diabetes mellitus,and to investigate the effects of oxidative stress and vascular endothelial function on the development of arteriosclerosis.Methods 168 patients were devidid into normal control(n=40),hypertension(n=70) and hypertension complicated with type 2 diabetes mellitus group(n=58).The serum NO,MDA and SOD were measured by colorimetric method respectively,and BaPWV were recorded by an automatic arterial stiffness measurement device.Results Compared with the control group,serum MDA,BaPWV were significantly higher and SOD,NO was lower(P<0.05) in the hypertension group and the hypertension complicated with type 2 diabetes mellitus group.Compared with the hypertension group,serum MDA,BaPWV were significantly higher and SOD,NO was lower(P<0.05) in the hypertension complicated with type 2 diabetes mellitus group.Correlation analysis showed that BaPWV was positively correlated with age,systolic blood pressure,dilated blood pressure,cholesterol,fasting blood glucose(FBG),high-sensitivity C-reactive protein(hs-CRP),serum MDA(r=0.418,0.672,0.469,0.179,0.392,0.277,0.571,all P<0.05),and was negatively correlated with serum SOD and NO(r=-0.438,-0.571,all P<0.05).The analysis of multiple stepwise regression showed that BaPWV was positively correlated with systolic blood pressure,MDA,FBG and age.Conclusion Arterial elasticity significantly decreased and was correlated with increase of oxidative stress and reduction of vascular endothelial function in patients with hypertension complicated with type 2 diabetes mellitus,suggesting that oxidative stress and endothelial function plays an important role in the development of arteriosclerosis.