Pb(ZrxTi1−x)O3 (PZT, x=0, 0.8, 1) thin films on fused quartz and Pt-coated Si substrates were prepared by a modified sol-gel process. Without using reflux and distillation to remove water. Phase structure, refractive indices n of amorphous and polycrystalline PZT thin films were obtained by X-ray diffraction, spectroscopic ellipsometry, and UV-VIS spectroscopy. PbZrO3 thin films on fused quartz substrates annealed at various temperatures, the absorption edges shifted is mainly due to phase structure changed from amorphous to polycrystalline. The refractive indices n of crystalline PbZrO3 thin film on Pt-coated Si substrates, compared with that of crystalline thin films of PbTiO3 and PZT80/20 were discussed.