Perrhenate anion was extracted by extractant N1923 in sulfuric acid solution at ionic strength from (0.2 to 2.0) mol.kg(-1). Molalities of perrhenate after extraction were measured in sulfuric acid aqueous system from (278.15 to 303.15) K. Standard extraction constants K-0 were obtained by polynomial approximation method at various temperatures. Thermodynamic properties were investigated in the extraction process.