Aim To evaluate the mechanism of vascular endothelial growth factor (VEGF) on prevention of restenosis after angioplasty. Methods The recombinant adenovirus containing the cDNA for hVEGF165 was constructed and infected vascular smooth muscle cell(VSMC)in vitro. 72 hours after the infection the conditioned medium containing VEGF was collected. Then the VSMC and human umbilical vein endothelial cell(hUVEC) were divided into control group,H 2O 2 treated group and H 2O 2+VEGF treated group to observe the proliferation and apoptosis by WST-1 method,TUNEL and FCM. Results To hUVEC,the OD value wasless frequent in the H 2O 2 treated group than that in the control and H 2O 2+VEGF treated group,the apoptosis was markedly superior in H 2O 2 treated group compared with control and H 2O 2 + VEGF-treated group. To VSMC,the changes of OD value and apoptosis were contrary to hUVEC. Conclusions H 2O 2 stimulated the proliferation of VSMC and induced the apoptosis of hUVEC, inhibited the proliferation of hUVEC and the apoptosis of VSMC, improved the restenosis. VEGF inhibited the effect of H 2O 2 on hUVEC and VSMC, and prevented restenosis. These results offered further theoretical evidence for VEGF on the prevention of restenosis after angioplasty.