TiO(2) thin films were prepared by sol-gel method. The structural investigations performed by means of X-ray diffraction (XRD) technique and scanning electron microscopy (SEM) showed the shape structure at T = 600 degrees C. The optical constants of the deposited film were obtained from the analysis of the experimentally recorded transmittance spectral data in the wavelength of 200-3000 nm range. The values of some important parameters of the studied films are determined, Such as refractive index n and thickness d. In this work, using the transmission spectra, we have calculated the dielectric constant (epsilon(infinity)) for four layered TiO(2) films; a simple relation is suggested to estimate the third-order optical nonlinear susceptibility chi((3)), it has been found that the dispersion data obeyed the single oscillator of the Wemple-DiDomenico model, from which the dispersion parameters and high-frequency dielectric constant were determined. The estimations of the corresponding band gap Eg, chi((3)) and epsilon(infinity) are 2.57 eV, 0.021 - 10(-10) esu and 5.20, respectively. (c) 2008 Elsevier B.V. All rights reserved.