Isothermal vapor-liquid equilibrium data for the binary mixture of 1,1,1-trifluoroethane (HFC-143a) + 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 van der Waals mixing rule. Calculated results showed good agreement with experimental data. Azeotropic behavior was not found in the temperatures studied here.