Abstract: The condition for the preparation of the electrodes of polycrystalline TiO₂ film on Ti foil was studied. It was found that the adhesive problem of the film with the substrate metal during the reaction of thermal oxidation of Ti and reduction of TiO₂ film might be solved by adding small amount of water vapor to the fluxional gas. Photosensitive electrodes with different thicknesses of film had been prepared. The relation between the thickness of film and photocurrent had been studied. By means of thermal conductivity detector, we studied the reducing condition of TiO₂ in hydrogen ambient. The influences of the different reducing temperature of TiO₂ on photocurrent were investigated. Using the TiO₂ electrode prepared, we have photoelectrolyzed water by sunlight with an energy conversion efficiency of 1.2%.