Epitaxial growth of cubic Mg0.33Zn0.O-67 films on MgO (1 0 0) substrate by metalorganic chemical vapor deposition (MOCVD) was reported. X-ray diffraction (XRD) omega-scans and phi-scans demonstrate the films exhibit single (2 0 0) orientation and highly uniform in-plane orientation with four-fold symmetry. The epitaxial relationship between the layer and substrate is MgZnO (1 0 0)//MgO (1 00). Smooth surface with the rms roughness of 1.8 nm in 5 x 5 mu m area is obtained. Atomic force microscopy (AFM) reveals formation of islands attributed to the strain in the epitaxial MgZnO films. These results demonstrate the high quality single crystal Mg0.33Zn0.67O films and their potential in high-performance deep ultraviolet optoelectronic devices. (C) 2010 Elsevier B.V. All rights reserved.