An LKB flow microcalorimeter, model 2277, has been used to deter-mine the excess enthalpies, as a function of concentration at atmospheric pressure and 298.15 K, for the following binary mixtures : 1-decene, 1,5-hexadiene, 1,7-octadiene and cyclohexene + benzene or + tetrachloromethane. These data and the data available in the literature on molar excess enthalpies, molar excess Gibbs energies, activity coefficients, and partial molar excess enthalpies at infinite dilution have been interpreted with the DISQUAC group contribution model.