Complex films composed of nanoscopic particles of phthalocyanine and titanium dioxide have been successfully prepared for the first time by coating the mixed colloids of titanium dioxide and phthalocyanine on glass substrates. The obtained transparent blue complex films decolored obviously when illuminated with UV light due to the W-light induced catalysis of the titanium dioxide particles for the oxidizing decomposition of phthalocyanine. The complex films and their decoloration were characterized by transmission electron microscope; X-ray diffraction patterns, W-visible spectra, and FTIR spectra.