We have applied the analytic fluctuation term developed by the authors to SAFT EOS to describe calorimetric properties correctly. The fluctuation term was found to qualitatively account for density localization effect at near critical region in lattice fluid theory. In this work, the fluctuation term is readily incorporated to SAFT EOS by replacing volume fraction of the term with packing density and the temperature dependency of probability of clustering is modified to eliminate undesirable feature in isobaric heat capacity shown in our previous work. This improvement closely reproduces the flatness of the coexistence curve including critical isotherm. The model contains 6 adjustable parameters and these parameters are optimized to fit correlations of experimental saturated liquid density, vapor pressure, supercritical PVT data and critical points. A comparison is made for light gas and some polar compounds. The model gives good fits to these properties and predicts heat of vaporization closely.