Colloidal TiO2 was prepared by hydrolyzing tetra-n-butyl titanate. PSS/TiO2 composite films were fabricated through the electrostatic self-assembly multilayer process. Both the colloidal TiO2 and the composite films were characterized with a UV-vis spectrophotometer and a fluorescence spectrophotometer respectively. The ultraviolet-visible absorption spectrum of the colloidal TiO2 shows that the absorption onset shifts to blue and that quantum size effect can be observed. The photoluminescent spectrum of the colloid shows that the shortest luminescence wavelength is 371 nm and that the photoluminescence is within the blue part of the spectrum. The photoluminescence behavior of the PSS/TiO2 composite film is similar to that of colloidal TiO2, and the luminescence of thin films mainly results from TiO2. However, PSS in the films has some influence on the photoluminescence behavior of the films.