A series of Dy-doped tungsten trioxide (WO3) nanopowders were synthesized via dipping the WO3 into Dy(NO3)(3) solution. The WO3 nanoparticles were freshly synthesized through precipitation process from Na2WO4 and hexadecyltrimethylammonium bromide (CTAB). The obtained samples were characterized by X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), diffuse reflectance absorption spectroscopy (DRS) and liquid nitrogen adsorption-desorption. Its photoactivity was evaluated through the photodegradation of Rhodamine B (RB) in aqueous solution. The effects of photoreaction conditions on the photoactivity of the obtained samples were investigated in detail. The experimental results indicated that Dy-doping not only improved the light absorption of WO3, but also enhanced the photoactivity and photostability of WO3. (c) 2007 Elsevier B.V. All rights reserved.