A poly-peroxotitanic acid (PPT acid) gel was prepared by dissolving Ti(OBun)(4) in H2O2 solution. Using the sol obtained after dissolving the gel in diluted H2O2 solution, amorphous and anatase TiO2 films were prepared on ITO-coated glass substrates by spin coating technique and heat-treatment. The films crystallized into anatase phase above 350 degrees C. Electrochemical and electrochromic properties of amorphous and anatase films, obtained at 150 and at 450 degrees C, respectively, were investigated by cyclic voltammogram (CV) and in situ monochromatic transmittance measurements in propylene carbonate (PC) solution containing 1 mol/l LiClO4. Both films were found to show reversible gray coloration upon Li+ ion intercalation. However, charge capacity and coloration efficiency of the amorphous film was greater than those of the anatase film.