CuAlO2 thin films were prepared by the radio frequency magnetron sputtering method. The effects of the working gas pressure on structure, optical and electrical properties of the films were investigated. The deposition rate increases with decreasing working gas pressure from 4.0 to 0.5 Pa. The X-ray diffraction (XRD) patterns show that the CuAlO2 pure phase is achieved for all films and a preferred growth orientation [001] is evidenced with decreasing working gas pressure. Furthermore, corresponding to the anisotropic electrical property of CuAlO2 thin film, the highest electrical conductivity measured at room temperature is about 1.6 x 10(-2) Scm(-1) for the film deposited at 0.5 Pa. The E-gd and E-gi are around 3.55 and 2.00 eV for CuAlO2 thin films with difference working gas pressure. (C) 2009 Elsevier B.V. All rights reserved.