Titanium dioxide (TiO 2 ) films were prepared by anodization of titanium foils at different voltages in dilute NaOH solutions and characterized by XRD and scanning electron microscopy (SEM) techniques. The thin TiO 2 films are mainly composed of anatase phase in the form of nano-crystallites. The photoelectrochemical behavior and photocathodic protection effect for these films were also investigated in 3% NaCl solutions by using electrochemical measurement techniques and coupling test. The tremendous decrease of film resistance and open circuit potential of each TiO 2 film takes place under ultraviolet (UV) illumination. TiO 2 film formed at 120V can serve as photoanode and supply a protective photocurrent about 8μA/cm 2 to carbon steel, when it is connected to carbon steel in test solution with an area ratio of 2:1. But TiO 2 films can accelerate the corrosion of carbon steel in the dark. In addition, electrochemical impedance spectroscopy (EIS) characteristics and coupling behaviors for TiO 2 films were discussed in detail.