Heats of mixing for the 1,2-dichloroethane-n-heptane, 1,2-dichloroethane-n-butanol and n-heptane-n-butanol systems were measured at 15 ℃, 25 ℃, 35 ℃ and 45 ℃. From the heats of mixing, partial heats of mixing were calculated, and then excess thermodynamic properties for each binary solutions were calculated. Using the partial excess Gibbs free energy, the values of isothermal vapor-liquid equilibrium were estimated. The calculated excess Gibbs free energy and isothermal vapor-liquid equilibrium data from heats of mixing were compared with those by total pressure method at 35 ℃ and 45 ℃. Furthermore, the isobaric vapor-liquid equilibrium data were estimated at 150 ㎜Hg and 300 ㎜Hg.