Combining thermodynamic database and electrochemical measurements, CeF3 thermodynamics properties were determined between 1113 K and 1233 K in LiF-CaF2 solution. First, standard potentials of CeF3/Ce were calculated in different reference states: liquid and solid, and infinite dilution. Then activity coefficients of CeF3 were estimated in the different reference states and for different composition scales: molarity, molality and molar fraction. Finally, constants which interconnected the infinite dilution reference state and the solid and liquid reference states were evaluated. (C) 2017 The Electrochemical Society. All rights reserved.