The aim of this work was to indicate some thermodynamic models based on the formalism ＇Equation of state-Excess function＇ able to represent thermodynamic properties of complex systems. First, we have developed the characteristics of the corrected Peng-Robinson equation of state for pure components as well as the conditions of its extension to mixtures by using excess function models such as those of van Laar, NRTL, Adachi-Sugie, Schwartzentruber-Renon and that of the ＇Surrounded Molecule＇. Afterwards, we have studied the simultaneous representation of vapor-liquid equilibria and mixing enthalpies of binary systems containing non-polar, polar or associated compounds by using a temperature-dependence of the parameters for all models considered. The obtained results allow thus to establish what classes of compounds need the use of excess functions depending of one, two or three binary interaction parameters.