Tungsten oxide nanowires have been prepared by heating a tiny tungsten wire partly wrapped with melted born oxide (B2O3) vitreous powder at 1600 degreesC in nitrogen atmosphere. The nanowires exhibit a well crystallized one-dimensional structure with 10-30 nm in diameter and 2-5 mum in length. A monoclinic crystalline structure could be established by high-resolution transmission electron microscopy study. (C) 2003 Elsevier Science B.V. All rights reserved.