An oxide photocatalyst Bi2WO6 with corner-shared WO6 octahedral layered structure was synthesized. Its band gap was determined to be 2.69 eV from UV - vis diffuse reflectance spectra. The photocatalyst showed not only the activity for photocatalytic O-2 evolution with the initial evolution rate of 2.0 mumol/h but also the activity of mineralizing both CHCl3 and CH3CHO contaminants under visible light irradiation. Meanwhile, wavelength dependence of CH3CHO decomposition was observed, which indicated that the photocatalytic activity of the photocatalyst was in good agreement with its light-absorption ability.