W18O49 nanowires are simply synthesized by the reaction between water vapor and tungsten powders in tube furnace at a low temperature of 600 degrees C. The nanowires have diameters of 20-50nm, lengths several micrometers. XRD, TEM and SAED results show that the nanowires are of single crystalline monoclinic W18O49 structures with the growth direction [010]. The growth mechanism is analyzed. We investigate the temperature dependence electrical transport properties of individual W18O49 nanowires. The conductivity is 2.58 Omega(-1) cm(-1) at 290 K and 42.35 Omega(-1) cm(-1) at 500 K, respectively. And the electron activation energy is calculated to be about 0.26 eV. (C) 2007 Elsevier B.V. All rights reserved.