A novel CdS/La2Ti2O7 nanocomposite photocatalyst working under visible light was prepared by a simple sonochemical coupled method. The catalyst was characterized by powder X-ray diffraction, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and UV-vis diffuse reflectance spectroscopy. The nanocomposite exhibited a strong photocatalytic activity for decomposition of methyl orange (MO) under UV and visible light irradiation. Moreover, the nanocomposite with La/Cd = 1:3 shows the highest photocatalytic activity. The enhanced photocatalytic performance might be attributed to the layered structure of CdS/La2Ti2O7 nanocomposites and the matched band potentials of the two semiconductors. (C) 2011 Elsevier B.V. All rights reserved.