Isothermal vapor-liquid equilibrium was measured for 2-methylpropane + 1,2-ethanedithiol, 2-methylpropane + 2-methyl-2-propanethiol, n-butane + 1,2-ethanedithiol, and n-butane + 2-methyl-2-propanethiol at 346.97 K with a static total pressure apparatus. The measured data were reduced with Barker's method to obtain phase equilibrium data. The Legendre polynomial, Wilson, NRTL, UNIQUAC, UNIFAC, and Cosmo-SAC activity Coefficients in infinite dilution and possible model parameters were reported. All binary data showed a positive deviation from Raoult's law,