Abstract: Polypyrrole（PPy）-TiO₂ nanocomposite film was prepared through the in-situ polymerization of pyrrole in the presence of TiO₂ sol.The self-assembled film was characterized by UV-Vis and IR spectroscopy,atomic force microscopy,electrochemical and photoelectrochemical measurements.Due to the interaction between PPy and TiO₂ in the nanocomposite film,there is a blue shift for the π→π^* transition,and there are shifts of the redox peaks in cyclic voltammogram relative to those in the PPy film.Photoelectrochemical experiments revealed that PPy-TiO₂ nanocomposite film showed a higher photoelectrochemical response than that of PPy film fabricated under the same condition.