ZnO nanorods had been successfully prepared by annealing the precursors, which are produced by the chemical precipitation method. The annealing temperature is found to be a key parameter for the preparation of ZnO nanorods. The largest ratio of the length to diameter for nanorods has been obtained at the annealing temperature of 400 degrees C. The microstructure of the resultant nanorods was studied by means of X-ray diffraction, transmission electron microscopy and photoluminescence spectra. The UV and visible emission are observed at room temperature. Spectra analyses show that the green emission depends strongly on the annealing temperature. The green and the yellow emission are attributed to the single ionized oxygen vacancy Vo(+) and the interstitial oxygen Oj(-), respectively. (c) 2005 Elsevier B.V. All rights reserved.