Thorium oxide is relevant both for nuclear fuel applications and solid oxide fuel cell (SOFC) technology. It is a refractory material with a cubic structure up to its melting temperature (3663K). Thorium oxide has several important advantages such as low thermal expansion coefficient, high thermal conductivity and high thermodynamic stability. Despite these advantages, it is mostly used as a structural material in MOX-T nuclear fuels. Nevertheless, its compatibility with metals is of scientific and technological importance since rare earth, 3+, doped thorium oxide solid solutions are oxygen ion conductors which could be used as SOFC's and oxygen sensors. In the present study the wetting kinetics in the ThO2/Me (Me=Al, U, Ce) systems was investigated at elevated temperatures and high vacuum using the sessile drop technique. Interface chemical reactions were characterized by electron microscopy and X-ray diffraction analysis. The ThO2/Melts interactions and the apparent contact angle are explained using classical thermodynamics.