Pb(Mg1/3Nb2/3)O-3-PbTiO3 (PMN-PT) thin films were prepared by spin coating using aqueous solutions of metal salts containing polyvinylpyrrolidone, where niobium oxide layers and lead-magnesium-titanium oxide layers were laminated on Pt(111)/TiOx/SiO2/Si(100) substrates and fired at 750 degrees or 800 degrees C. 250 +/- 20 nm thick 0.7PMN-0.3PT thin films of a single-phase perovskite could be prepared, and the film fired at 750 degrees C had dielectric constants and dielectric loss of 1900 +/- 350 and 0.13 +/- 0.03, respectively, exhibiting polarization-electric field hysteresis with a remanent polarization of 5.1 mu C/cm(2) and a coercive field of 21 kV/cm.