CoO nanowires with diameters of 50-80 nm, and lengths of up to more than 5 mu m have been successfully synthesized by a simple environmentally friendly molten salt route, in which the precursor CoCO3 nanoparticles are decomposed to form high-purity CoO nanowires in NaCl flux. The structure features and morphology of the as-prepared CoO nanowires were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution TEM (HRTEM), and selected area electron diffraction (SAED). The chemical composition and oxidation state of the prepared nanowires were systemically studied by X-ray photoelectron spectra (XPS) and laser Raman spectroscopy. The results indicated that the as-prepared CoO nanowires were composed of pure cubic CoO phase. The growth mechanism of the synthesized nanowires was also discussed in detail based on the experimental results. (C) 2009 Elsevier B.V. All rights reserved.