Thermodynamic properties of rare-earth Ln(2)CuO(4) (Ln = Nd, Sm, Eu), Ho2Cu2O5 and Ln(2)BaCuO(5) (Ln = Nd, Sm, Eu, Ho, Yb) cuprates were determined using the electromotive force method with a fluorine-ion electrolyte in the temperature interval of 1000-1230 K. The thermodynamic data obtained by different experimental methods were compared.