Uniform TiO 2 /SiO 2 composite films were prepared on ITO substrates by electrodeposition, and highly photoelectrocatalytic (PEC) activity of the composite films was observed toward the degradation of methyl orange (MO) in aqueous solutions. It was further found that their PEC activity was dependent on the electrodeposition parameters including deposition time, solution pH and SiO 2 content. Under the optimized condition, the PEC degradation of MO on TiO 2 /SiO 2 composite film electrode could be enhanced about 14 times relative to that on neat TiO 2 film electrode. The high PEC activity of the TiO 2 / SiO 2 composite film electrode was mainly attributed to the enhancement of the charge separation of photo-generated electron-hole pairs by the dispersion of SiO 2 nanoparticles in the TiO 2 matrix with the aid of the applied electric field.