An ionic liquid (IL) H.PReO4 (N-hexylpyridine rheniumate) was prepared. The density and Surface tension of the IL were determined in the temperature range of (293.1.5 to 343.15) K. The ionic Volume and surface entropy of the IL were estimated by extrapolation. In terms of Glasser's theory, the standard molar entropy and lattice energy of the IL were estimated. Using Kabo's method and Rebelo's method, the molar enthalpy of vaporization of the IL, Delta H-g(1)m(0)(298 K), at 298 K and Delta H-g(1)m(0)(T-b), at hypothetical normal boiling point, were estimated, respectively. According to die interstice model, the thermal expansion coefficient of IL HPReO4, alpha, was calculated, and in comparison with experimental value, the magnitude order is in good agreement by 3.32 %.