The lack of compatibility between reactive melts, such as aluminum, and crucible materials is a recurrent problem in metallurgical practice. Thermodynamically stable oxides are commonly used as crucible materials. In the present work, the interaction of the quasi-binary oxides (MgAl2O4 and YAG) with liquid Al was studied by the sessile drop method. In both systems, the contact angle decreases from 120 to 40A degrees in the 1273-1523 K temperature range. No presence of Mg in Al was detected after the interaction between MgAl2O4 and liquid Al, whereas a detectable amount of Y was dissolved in the melt following the interaction between YAG and molten Al. The differences in the interaction at the interface in the studied systems are attributed to the thermodynamic properties of the ternary Al-Mg-O and Al-Y-O systems.