Abstract: Nanocrystalline TiO₂ films were prepared by sol-gel method, powder-coating method and magnetic sputtering. The surface and crystal structure of the TiO₂ films were analyzed by X-ray diffraction, scanning electron microscope and transmission electron microscope. It is found that the TiO₂ films are mainly anatase structure with nano-size grains. Structure of the TiO₂ films and behavior of the NPC solar cell composing of the TiO₂ films were analyzed in detail. It is found that the multilayer （compact layer and porous layer） TiO₂ films is better than any single layer TiO₂ film for NPC solar cell.