CdIn2O4 thin films were prepared by direct-current (DC) reactive magnetron sputtering. The structure, surface morphology and the chemical composition of the thin films were analyzed by X-ray diffraction (XRD), atomic force microscope (AFM) and X-ray photoelectron spectroscopy (XPS), respectively. The electrical properties of the films prepared in different oxygen concentration and annealing treatment were determined, and the effects of the preparing conditions on the structure and electrical properties were also explored. It indicates that the CdIn2O4 thin films with uniform and dense surface morphology contain mainly CdIn2O4, In2O3 phases, and CdO phase is also observed. The XPS analysis con firms the films are in oxygen-deficient state. The electrical properties of these films significantly depend on the preparing conditions, the resistivity of the films with the oxygen concentration of 4.29% is 2.95 x 10 (4) Omega cm and the Hall mobility is as high as 60.32 cm(2)/V s. Annealing treatment can improve the electrical performance of the films. (C) 2008 Elsevier B.V. All rights reserved.