In this paper ZnO films are grown on GaAs/Al2O3 substrates at different temperature by metal-organic chemical vapor deposition (MOCVD). The GaAs/Al2O3 substrates are formed by depositing GaAs layer (similar to 35 nm) on the Al2O3 substrate. The results of X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) demonstrate that most of the Ga and As atoms form Ga-As bond and the GaAs layer does not present any orientation. The characters of the ZnO films grown on GaAs/Al2O3 substrates are investigated by XRD, photoluminescence (PL), atomic force microscopy (AFM) and Raman scattering. Compared with ZnO film grown on Al2O3 substrate, ZnO film prepared by our fabrication scheme has good crystal and optical quality. Meanwhile its grain size becomes bigger according to the AFM image. Raman analysis indicates that the intrinsic defects and the in-plane tensile stress are obviously reduced in ZnO/GaAs/Al2O3 samples. (C) 2009 Elsevier B.V. All rights reserved.