The photoelectrochemical oxidation of nitrite ion on a rutile form of a TiO2 particulate film immobilized on a titanium plate (TiO2/Ti) with applying bias potential was studied. The experimental results indicate that the oxidation of nitrite ion is mainly affected by the applied potential and irradiation of power of light, and the oxidation is also independent of both nitrite ion concentration and pH. Theoretical analysis results correlate well with experimental ones, indicating that the reaction is of zero order with respect to the concentrations of nitrite ion and the hydroxyl ion. Meanwhile, the reaction is of 0.30 and 0.80 order with respect to the applying bias potential and the output power of light, respectively.