TiO2 films doped with SnO2 were prepared on quartz substrate by electrostatic self-assembly method in this paper. Atom force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and UV-Vis-NIR spectrophotometer were employed to characterize the microstructure and performance of the samples. Results of the optical absorption spectra and the measurement of photo-catalytic activity show that the photo-absorbency of the samples is greatly increased and the photo-catalytic activity of the films is well improved by SnO2-doping.