The magnetic photocatalyst, Fe3O4/BiOCl nanocomposite, was prepared and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and high-resolution TEM (HRTEM), physical property measurement system (PPMS). It was found that Fe3O4/BiOCl was an effective photocatalyst to degrade the organic dyes. Compared with the conventional core-shell magnetic photocatalysts, such as Fe3O4/TiO2 system which dramatically lost their intrinsically photocatalytic activity due to the introduction of the magnetic core, the as-synthesized Fe3O4/BiOCl reserved as high photocatalytic activity as that of BiOCl. The high catalytic activity possibly involved in a coupled structure and the special interfaces, that is, the probability of combination of the carriers could be reduced in this system. Moreover, the superparamagnetic Fe3O4/BiOCl can be not only easily recycled but also fluidized by applying an external magnetic field. (C) 2009 Elsevier B.V. All rights reserved.