92%Pb(Mg1/3Nb2/3)O3–8%PbTiO3 (PMNT) thin films have been prepared on Pt/Ti/SiO2/Si substrate with a LaNiO3 (LNO) buffer layer and on sapphire substrate by a chemical solution deposition method, respectively. X-ray diffraction analysis shows that the PMNT thin films on Pt/Ti/SiO2/Si substrate are polycrystalline with (110)-preferential orientation. Pt/PMNT/Pt capacitors have been fabricated and show a ferroelectric character with a spontaneous polarization (Ps) of 25.2 μC/cm2 and a remanent polarization (Pr) of 6.56 μC/cm2. The dielectric constant (εr) and the dissipation factor (tan δ) at 1 kHz are 680 and 0.014, respectively. The band-gap energy of the PMNT thin films on the sapphire substrate was found to be about 4.03 eV by the optical transmission spectra measurement. The optical constants (n, k) of the PMNT thin films in the wavelength range of 2.5–12.6 μm were obtained by infrared spectroscopic ellipsometry measurement.