Thin films of vanadium-titanium complex oxides were prepared on glass substrates from the mixture of peroxovanadate and peroxotitanate solutions by the spin coating method. Temperature dependence of the reflectance spectra for the thin films were investigated, and it was found that their reflectivities in the wavelength region from 700 to 1000 nm were reversibly increased over 45 degrees C. The changes in optical dielectric constants were estimated and discussed from a viewpoint of the practical applications as thermochromic smart windows. (c) 2008 Elsevier B.V All rights reserved.