The nature of TiO 2 films and sensitizer play significant roles in determining the overall efficiency and mechanical stability of dye sensitized solar cell. In this study, cis-RuL 2 (SCN) 2 , (L๏ผ2,2'-dipyridine-4,4'-dicarboxlic acid) was synthesized from 4-methylpyridine by the procedure of cross-coupling, oxidation, conjugation and ligand substitution. TiO 2 films were obtained by blending P25 and TiO 2 sol. To increase the photoelectric properties of the thin TiO 2 films, La(NO 3 ) 3 with different concentrations (0.1%, 0.3%, 0.5% and 0.7%) were added into the sol. Both undoped and doped samples of the thin films were sensitized by cis-RuL 2 (SCN) 2 and structurally characterized by X-ray diffraction, atomic force microscopy and X-ray photoelectron spectroscopy. In addition, the photoelectric properties of the TiO 2 electrodes were investigated. The results show that doping lanthanum ions made the grain size smaller and surface area larger. When the concentration dopant is 0.5%, the short circuit current and open circuit voltage of the TiO 2 film reach maximum. The short circuit current increases 0.54 mA/cm 2 more than that of undoped film, and the open-circuit voltage increases 30.41 mV more than that of undoped film.