Application of bias potential to the photocatalytic decomposition of aniline in aqueous solution was studied under various solution pH, bias potentials and concentrations of potassium chloride. The decomposition of aniline by UV/TiO2 process was found to be enhanced with the application of bias potential of lower voltages: however, the electrolysis of aniline became more dominant as the applying bias potential exceeding 1.0V. Based on the experimental results and calculated synergetic factors, the application of bias potential improved the decomposition of aniline more noticeably in acidic solutions than that in alkaline solutions. Decomposition of aniline by UV/bias/TiO2 process in alkaline solutions was increased to certain extent with the concentration of potassium chloride present in aqueous solution. Experimental results also indicated that the energy consumed by applying bias potential for aniline decomposition by UV/bias/TiO2 process might be much lower than that consumed for increasing light intensity for photocatalysis. (C) 2010 Elsevier B.V. All rights reserved.