AimTo investigate the effects of advanced glycation end products(AGE) and homocystein（Hcy）on the expression of vascular cell adhesion molecule-1(VCAM-1) mRNA via oxidative stress mechanism in human umbilical vein endothelial cell（HUVEC）.MethodsCollagenase was used to isolate the endothelial cell from human umbilical vein.RT-PCR was used to examine the expression of VCAM-1 mRNA.Inversion fluoescence microscope was used to observe the level of oxygen free radical.Results The expression of VCAM-1 mRNA was induced concentration-dependently by AGE(10－4～10－1 g/L) and Hcy(1.35×10－3～1.35 g/L); AGE combined with Hcy group could promote the expression of VCAM-1 mRNA respectively 7.78 times and 6.05 times in comparison with AGE group and Hcy group（1.09±0.18 vs 0.14±0.07；1.09±0.18 vs 0.18±0.06， P<0.01）; By comparison with AGE combined with Hcy group, the VCAM-1 expression of DPI group was obviously reduced(0.20±0.09 vs 1.19±0.23,P<0.01); In comparison with control group, AGE group and Hcy group could enhance oxygen free radical in HUVEC; The level of oxygen free radical in AGE combined with Hcy group was higher than that in AGE group and Hcy group; DPI could significantly inhibit the level of oxygen free radical.ConclusionAGE and Hcy can enhance the level of oxygen free radical in HUVEC and increase the VCAM-1 expression, and they have the cooperative effect; The enhancement of oxygen free radical is an important factor on the expression of VCAM-1 mRNA; The above process is realized possibly through activating the NADPH oxidase.