A novel Bi(2)WO(6)@carbon/Fe(3)O(4) nanostructure with a thin carbon interlayer was reported. Reactive carbon interlayer was introduced as a key component for the growth of Bi(2)WO(6) nanoplates on the magnetic Fe(3)O(4) microsphere. After the carbon layer was oxidized by the KMnO(4) in the basic solution, Bi(3+) ions could be adsorbed by the as produced -COO(-) groups and thus Bi(2)WO(6) nanoplates grew on the surface of the carbon/Fe(3)O(4) microspheres preferentially. The as-prepared nanocomposite, which could be easily recovered by a magnet, exhibited high efficiency in the photocatalytic decomposition of phenol with the assistance of H(2)O(2). The combination of photocatalyst and magnetic materials through a reactive carbon interlayer opens up a new route for the fabrication of complex and multifunctional nanostructure.