Nanowires were prepared by ethylene polymerization in situ with carbon nanotubes (CNTs)-supported Cp2ZrCl2 catalyst. It was found that the metallocene catalyst was first adsorbed on the surface of the CNTs and then the polymerization of ethylene was initiated. The resulting PE could encapsulate on the surface of the CNTs to form nanowire. The diameter of nanowire could be controlled easily by the polymerization conditions. The possible mechanism of formation of nanopolyethylene wire is proposed. (c) 2006 Wiley Periodicals, Inc.