Abstract: The photocatalytic oxidation technology of TiO2 has been widely studied as a potential method in treating organic pollutants in recent years. However, titanium dioxide shows photocatalytic activity only by irradiation of UV light due to its high intrinsic band gap, which restricts its use in the photocatalytic oxidation technique in practice. In this paper, titanium dioxide thin film and nitrogen doped TiO2 thin films, annealed at 300℃ and 500℃ for 0.5 h were prepared by multi-arc ion plating on glass substrates. The results show that the crystalline structure of nitrogen doped titanium dioxide thin films are noncrystal with their phase transform to anatase phase after being annealed at 500℃. The absorption edge of N-doped thin films prepared under optimal technological conditions has an obvious red-shift.