Polycrystalline CaCu3Ti4O12 (CCTO) films were grown on Pt/Ti/SiO2/Si substrates using pulsed laser deposition. The choice of optimal laser fluence was found to be important to the microstructure and dielectric properties of CCTO films. Thin films with a (2 2 0) preferential orientation were obtained in a narrow fluence range of 1.8-2.0J/cm(2). Moreover, the CCTO films deposited at 2.0 J/cm(2) showed high dielectric constant (2474) and low dielectric loss (0.05) at 10 kHz, which was ascribed to the improved crystallinity. (c) 2008 Elsevier B.V. All rights reserved.