Porous TiO2 films and smooth TiO2 films were fabricated by sol-gel dip-coating technique using titanium plate as support substrate. Photoelectrocatalytic (PEC) degradation of methyl orange was investigated in aqueous NaCl solution using the TiO2 films. PEC degradation efficiencies showed strong dependence on the concentrations of aqueous NaCl solutions and applied potentials. Photoelectrocatalytic activity of the porous TiO2 film was higher than that of the smooth TiO2 film at lower applied potential. 95.2% decolorization of the dye could be achieved in 50 minutes at applied potential of 0.6 V in 0.05 M NaCl solution on porous TiO2 films, while the efficiency was only 79.9% on smooth TiO2 films. Electrodegradation (ED) of these two film electrodes almost had no effect on methyl orange. Photocatalytic oxidation (PCO) degradation was 36.4% for the porous TiO2 thin film after 80 min, and 32.6% for the smooth TiO2 thin film during the same condition.