By means of concentration cells of the following type: Mg(s) |MgCl2 in (LiCl-KCl)eut (1) |Mg-Ga (1) the partial thermodynamic data of Mg in Mg-Ga liquid solutions have been obtained in the composition range 0. l≤xMg≤0.7 and at temperatures from 760 to 900 K. In addition, the enthalpies of mixing of liquid Gallium with liquid Magnesium have been measured calorimetrically at 973 K. The experimental values for the enthalpies of mixing from emf and calorimetric measurements are in good agreement. These values are compared with thermodynamic data reported in the literature and used for the calculation of thermodynamic data of intermetallic compounds existing in the Mg-Ga-system. Additionally, the heat of formation of Mg5Ga2 has been determined by solution calorimetry. The thermodynamic data of the liquid alloys can be described by an association model, and these results explain the possibility to obtain glassy metals by rapid cooling of these melts.