The TiO2-La2O3 pseudo-binary system is investigated via key experiments and thermodynamic modeling. The phase diagram data from literature are critically reviewed. Four key samples are prepared by mixing the pure oxides, heat-treated at 1473 K, 1623 K, 1673 K, 1733 K and 1873 K, respectively for 20 h and then are subjected to X-ray diffraction (XRD) analysis for phase identification and to differential scanning calorimetry (DSC) for measurements of phase transition temperatures. The thermodynamic optimization of the TiO2-La2O3 system is performed by considering the experimental data from the literature and the present work. A set of consistent thermodynamic data for the TiO2-La2O3 system is obtained by optimization of the selected experimental data. The calculated phase diagram explains the experimental data very well. (C) 2012 Elsevier B.V. All rights reserved.