Lead-free ferroelectric K0.5Na0.5NbO3 (KNN) thin films have been prepared on Pt/TiO2/SiO2/Si substrates by pulsed laser deposition process. The structures, crystal orientations and electrical properties of thin films have been investigated as a function of deposition temperature from 680 degrees C to 760 degrees C. It is found that the deposition temperature plays an important role in the structures, crystal orientations and electrical properties of thin films. The crystallization of thin films improves with increasing deposition temperature. The thin film deposited at 760 degrees C exhibits strong (0 0 1) preferential orientation, large dielectric constant of 930 and the remnant polarization of 8.54 mu C/cm(2). (C) 2011 Elsevier B. V. All rights reserved.