Abstract: LiTaO₃ thin films were deposited on FTO conductive glass substrates by sol-gel method. The surface morphology, crystallization and optical properties of the films were analyzed by TG-DTA, SEM, XRD and UV-Vis spectroscopy. The results show that the films annealed at 650 °C have strong preferred orientation in (006) direction, uniform surface morphology and less cracks. The half-peak width of LiTa₃O₈ impurity peak and optical band gap E_g are obviously affected by the crystallization properties of LiTaO₃ thin films. Optical band gap E_g increases with the decrease of half peak width of impurity LiTa₃O₈ peak. The blue shift of the optical band gap E_g increases from 3.87 eV to 3.91 eV.