Aim To study the effects of NAD(P)H oxidase subunits p22phox on endothelial reactive oxygen species (ROS) induction and cell apoptosis induced by high-glucose. Methods Human umbilical vein endothelial cell (hUVEC) were divided into four groups:control group,high glucose group,siRNA group and high glucose+siRNA group. Expression of p22phox,intracellular ROS level,and cell apoptosis in hUVEC were detected by Western-blot and flow cytometry respectively. Results p22phox-siRNA could induce NAD(P)H oxidase subunit p22phox gene silence,high glucose could induce p22phox expression. Compared with high glucose group,ROS level and cell apoptosis was decreased in high glucose+siRNA group(P<0.05). Conclusion Inhibiting p22phox expression could decrease ROS level and cell apoptosis induced by high-glucose.