Temperature dependence of heat capacity of the Eu2Zr2O7 and Y2O3 is measured in the temperature range of 298.15-1373 K by differential scanning calorimetry (DSC). Phase transformation in the Eu2Zr2O7 was experimentally studied using differential thermal analysis (DTA) up to 2173 K and temperature of pyrochlore to fluorite transition was established to be 2128 K. Eutectic reaction was determined by DTA to be 2326 K. Peritectoid reaction F + B = C was established to occur at similar to 1823 K based phase equilibrium studies. Phase compositions were determined by SEM/EDX. The obtained results for heat capacity of the Eu2Zr2O7, temperatures of transformations and phase compositions were used to optimise thermodynamic parameters of the Eu2O3-ZrO2 system. (C) 2013 Elsevier B.V. All rights reserved.