This article discusses an analytical method for characterizations of TiO2 thin films and determinations of the degree of their inhomogeneity. The TiO2 films were prepared by a pulsed dc magnetron sputtering with an operating pressure as a main experimental parameter. The obtained films were primarily characterized for film crystallinity, microstructures and optical properties by spectroscopic ellipsometry. The measured ellipsometric data were analyzed by the single-, the double, and the triple-layer models in order to match with the inhomogeneous film structure proposed in the Thornton structure zone model. The results were then compared with those obtained from grazing-incidence X-ray diffraction, field-emission scanning electron microscopy and high-resolution transmission electron microscopy. The study revealed that the pulsed dc sputtered TiO2 films could be best described by the inhomogeneous triple-layer physical model. Although the films deposited at lower operating pressure had a dense structure with a mirror-like surface topography, the films deposited at higher operating pressure had the porous structure with the rough surface and the void. (C) 2011 Elsevier B.V. All rights reserved.