Isothermal vapor-liquid equilibrium data were determined for the binary systems of 1,1,1-trifluoroethane (HFC-143a) + 1,1,1,2-tetrafluoroethane (HFC-134a) and 1,1,1-trifluoroethane (HFC-143a) + 1,1-difluoroethane (HFC-152a) at 273.15, 293.15, 303.15, and 313.15 K in a circulation-type equilibrium apparatus. The experimental data were well correlated with the Carnahan-Starling-De Santis (CSD) equation of state within +/-1.0%. Azeotropic behavior has not been found in any of these mixtures.