One of the major problems of the metallurgical practice is a lack of compatibility between reactive liquid melts, such as aluminum, and the material of a crucible. The thermodynamically stable oxides may be adequate as a structural material for this application. In order to check the compatibility between the quasi-binary oxides such as Spinel (MgAl2O4( and YAG (Y3Al5O12) and liquid Al at high temperatures, wettability study accompanied with interface characterization were performed. In both systems aluminum doesn’t wet the substrate up to 1223K, but the contact angle decreases with increasing temperature and the values of the final contact angle (similar for the both systems) of about 40 º were obtained at 1523K. The interaction between the substrates and liquid Al leads to the formation of Al2O3. The presence of Mg in the melt after interaction between Spinel and liquid Al system wasn’t detected, while for the YAG/Al system minor amounts of Y were dissolved in the melt. The differences in the mechanism of the interaction and in the nature of the reaction products in the studied systems are attributed to the thermodynamic properties of the ternary Al–Mg–O and Al–Y–O systems.