Abstract: The nanoscale TiO₂ thin films have been successfully fabricated by liquid phase deposition(LPD) method.The microstructure,morphology,and phase composition were investigated through Scanning Electronic Microscopy(SEM) and X-ray Diffraction Patterns(XRD) method.The photoelectronchemical properties,such as polarization curves,variations of open-circuit potential function with time in presence and absence of simulated solar light(metal halogen lamp) were studied.The experimental results showed that anatase could be obtained after the deposited thin films being annealed at 500℃.The corrosion potential of the thin film shifted from 100 mV to-114 mV under illumination of simulated solar light.The changes of the open-circuit potential of the thin films decreased under illumination and increased in the dark.The mechanism of the cathodic protection of TiO₂ nanoscale thin films for 304 stainless steel was studied in this paper.