The atomic force microscopy (AFM), the X-ray diffraction with glancing input angle (GXRD) and the cathodo-luminescence (CL) spectra of a ZnO film on Si, annealed at different temperatures, were measured. The results showed that, the crystal quality of the film improved with increasing the annealing temperature, while the hexagonal phase of the ZnO film transformed into a kind of mixture phase including a hexagonal and a trigonal phase, after annealing at 800 degreesC for I h. The CL spectrum also shows the intrinsic emission bands of ZnO and Zn2SiO4, in which the ZnO is the main source of the spectrum. Increasing the temperature continuously up to 950 degreesC changed the main source of sample's luminescence from the emission of ZnO to the emission of zinc silicate. This indicates a creation of new ternary compound Zn2SiO4 in the film. (C) 2002 Elsevier Science B.V. All rights reserved.