Tin oxide (SnO2) thin films were fabricated on quartz substrates by pulsed laser deposition followed by annealing at different temperatures in oxygen ambience. The structural property was investigated by X-ray diffraction, from which a clear annealing induced crystal grain growth was observed. Fourier transform infrared spectroscopy and X-ray photoemission spectroscopy were employed to study the oxygen vacancy density of the annealed SnO2 thin films. An interesting annealing temperature dependent oxygen vacancy behavior of these SnO2 thin films was revealed and attributed to the competition between the desorption of oxygen species and the oxidation effect occurring during the annealing process. (C) 2010 Elsevier B.V. All rights reserved.