Novel WO3/TiO2 microrods and microplates are prepared by simple precipitation and calcination processes. The microstructures are assembled from WO3 and TiO2 nanoparticles. They were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) coupled with energy dispersive X-ray (EDX) analysis, transmission electron microscopy (TEM) and fluorescence emission decay spectra. The as-prepared composites show enhanced photoactivity than that of WO3 and TiO2 in the photocatalytic oxidation of water to O-2. The formation mechanism of assembled structures and their enhanced photoactivities are discussed based on characterization results. (C) 2011 Elsevier B.V. All rights reserved.