In this paper, vanadium oxide (V2O5) was introduced between the active layer and top electrode as buffer layer. The structure of the photovoltaic device is ITO/TiO2/P3HT: PCBM/V2O5/Ag. TiO2, which was prepared in sol-gel method, was used as an electron selective layer. The performance of photovoltaic device with V2O5 layer is dramatically improved compared with that without V2O5. The power conversion efficiency is improved from 0.79% to 2.58% under 100 mWcm2 white light illumination in ambient air.