The undoping ZnO emitting films were deposited on Si substrates by de reactive sputtering. There are two peaks of photoluminescence (PL), centered at 3.18 eV (ultraviolet): and at 2.38 eV (green), to be observed in the samples. We investigated the dependence of PL spectra on annealing temperature and annealing atmosphere. According to the calculation of defect levels and the relationship between PL spectra and annealing conditions, we supposed that the green emission of ZnO films corresponds to the local level composed of the antisite defect O-Zn. (C) 2001 The Electrochemical Society. All rights reserved.