Lanthanum-modified lead zirconate titanate (PLZT) thin films, with the La/Zr/Ti ratio being 9/63/37, were deposited on indium tin oxide (ITO)-coated glass substrate by R.F. magnetron sputtering method. Effects of heat-treatment conditions on the structure and chemical homogeneity of the PLZT thin films were investigated by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The PLZT thin films with desired perovskite structure were obtained after covered with lead oxide and then annealed at 625degreesC for 150 min. The binding energy of Pb-4f7/2, Ti-2p3/2, Zr-3d5/2, La-3d5/2, and O-1s in PLZT thin films were: 138.3, 455.7, 181.2, 835.9, and 529.4 eV, respectively. The excess lead oxide in the PLZT thin films promoted the perovskite structure formation, and baffled the movement of TiO2 and ZrO2 as well. A small quality of TiO2 and ZrO2 coexisted with PUT in the surface of samples. And the lack of oxygen inside the films resulted in the valence decrease of a little part of Ti's from +4 to +2. (C) 2004 Elsevier B.V. All rights reserved.