Abstract: Objective To study the effects of vascular endothelial growth factor (VEGF) gene transfer on hypoxia-induced apoptosis of neural stem cells in vitro. Methods C17.2 neural stem cells cultured in vitro were infected by recombinant adenovirus containing VEGF gene and cultured under hypoxic condition. VEGF expression in these cells was detected by Western blotting, and the apoptotic index was calculated from results of triphosphate-biotin nick end-labeling (TUNEL) assay. Flow cytometry was employed to examine the changes in the cell apoptotic rate after VEGF gene transfer, and the apoptotic bodies were observed under fluorescence microscope with Hoechst33342 staining. Results The expression of VEGF was significantly increased in pAdCMV VEGF165-infected cells, resulting in inhibition of the apoptosis of C17.2 neural stem cells induced by hypoxia manifested by a significantly lower apoptotic rate of the stem cells transfected by pAdCMV VEGF165 than that of the untransfected cells (10.38%±0.48% vs 19.98 %±0.55%, P<0.01) and of the cells transfected with pAdCMV VEGF165 along with VEGF anti-sense oligodeoxynucleotide (19.07%±0.64%, P<0.01) after hypoxia. Conclusions Recombinant adenovirus can efficiently mediate VEGF gene transfer into C17.2 neural stem cells, resulting in high expression of the exogenous VEGF in vitro, which effectively reduces C17.2 neural stem cell apoptosis induced by hypoxia.