Vacuum activation method was used to modify TiO2 to produce highly air stable V4+ and Ti3+ co-doped TiO2. The physicochemical properties of the catalysts were studied by a series of characterizations. The low valence Ti3+ and V4+ states were formed by vacuum activation and vanadium doping formed new impurity bands between CB and VB of TiO2, which narrowed the band gap and enhanced the absorption of visible light. Also, the V4+/V5+ and Ti3+/Ti4+ cations could reduce the e(-)/h(+) pair recombination rate to give high quantum efficiency.