Isothermal vapor-liquid equilibrium data for the binary mixture of propane (R290) + normal butane (R600) were measured at (273.15, 283.15, 293.15, 303.15, 313.15, and 323.15) K, respectively, The experiments were carried out using a continuous circulation-type equilibrium apparatus to measure temperature, pressure, and the compositions of the liquid and vapor phases. The experimental data were correlated with the Peng-Robinson equation of state (PR-EOS) using the Wong-Sandler mixing rule. The calculated results showed good agreement with experimental data. This system showed slightly negative deviation from Raoult's law and no azeotropes for all the temperature ranges studied here.