Boiling points of 9 binary systems（n-hexane-n-butanol, acetone-methanol, acetone-n-propanol, methanol-n-propanol, n-hexane-n-propanol, acetone-n-hexane, methanol-n-butanol, methanol-n-hexane, acetone-n-butanol） were measured at the 760 ㎜Hg. Using the Gautreaux & Coates equation, infinite activity coefficients of each system were calculated from the boiling poins curves of the 9 systems. Furthermore from the infinite activity coefficients Wilson parameters and isobaric vapor-liquid equilibria data were obtained. These data were compared with the experimental and reported data.