The results of studying the vaporization processes and thermodynamic properties of the TiO2-Al2O3 system in the temperature range 2250-2710 K using the high temperature mass spectrometric method were presented. Identification of the vapor composition over the system under the study and determination of the TiO2, TiO, and Al partial vapor pressures were carried out in the temperature range mentioned. The component activities and excess Gibbs energy were determined in the melts of the TiO2-Al2O3 system at the temperature 2345 K evidencing insignificant deviations from the ideality in the system under the study.