Using Mn(NO3)(2) and ozone as raw materials, beta-WO2 nanowires with diameters of about 6-12 nm, lengths of 2-5 mu m and surface area of 73.54 m(2) g(-1) were synthesized by a simple hydrothermal process. The influences of synthesis conditions such as hydrothermal temperature, reaction time and ozone were investigated, and the growth process of beta-MnO2 nanowires was discussed. The catalytic properties of beta-MnO2 nanowires for the degradation of phenol were evaluated. beta-MnO2 nanowires revealed good separability and remarkable catalysis for the degradation of phenol. (C) 2008 Elsevier B.V. All rights reserved.