The partial and total enthalpies of mixing of Si-C and Ni-C liquid alloys at 2000 K are determined by isoperibol calorimetry. The mixing enthalpies in these systems are found to be small and negative, in agreement with earlier results. The thennochemical properties of dilute Al-C solutions are studied at 1773 K for the first time. The mixing enthalpies of metal-carbon melts are estimated from the standard enthalpies of formation of metal carbides. The calculated mixing enthalpies of liquid metal-carbon alloys agree with experimental data.