Oriented CuO nanowires of 15-20 mu m in length were synthesized by heating copper grids under atmospheric conditions. The morphology, possible growth mechanism, electrical and catalytic properties of the nanowires were studied. The aspect ratio of the profile of the nanowires ranges from 1.3 to 2.2 indicating that the CuO nanowires are not columniform. The impurities in the copper grids play an important role in the growth of the nanowires. The transport measurement of a single CuO nanowire demonstrated that the nanowire exhibits a typical semiconductor behavior. The observed high catalytic oxidation of CO was attributed to the selectively exposed (-111) planes with more surface lattice oxygen of the nanowires. (C) 2013 Elsevier Ltd. All rights reserved.