A new non-cubic equation of state is proposed for calculation of the thermodynamic properties ofnonpolar and polar fluids and their mixtures,including,saturated vapor pressure,saturated liquid volume,saturated vapor volume,heats of vaporization and vapor-liquid equilibria.The new equation is derived from thegeneralized van der Waals partition function in which the repulsive terms are expressed with the Carnahan andStarling equation for hard spheres,and the attractive terms are made up of the dispersive energy and theChemical association energy. The rules of dependence of parameters α and σ and on temperature are considered broadly so that the newequation yields good agreement with experimental saturated properties of 20 nonpolar and 27 polar fluids in therange of reduced temperatures of 0.5 to 1.0 The new equation with parameters group-contributed generally givessatisfactory predictions on saturated properties. Correlations of vapor-liquid equilibrium data for alcohol-containing systems by using van d A new non-cubic equation of state is proposed for calculating the thermodynamic properties of nonpolar and polar fluids and their mixtures, including, saturated vapor pressure, saturated liquid volume, saturated vapor volume, heats of vaporization and vapor-liquid equilibria. The new equation is derived from the generalized van der Waals partition function in which the repulsive terms are expressed with the Carnahan and Starling equation for hard spheres, and the attractive terms are made up of the dispersive energy and the Chemical association energy. The rules of dependence of parameters α and σ and on temperature are considered broadly so that the new inequation yields good agreement with experimental saturated properties of 20 nonpolar and 27 polar fluids in therange of reduced temperatures of 0.5 to 1.0 The new equation with parameters group-contributed generally givessatisfactory predictions on saturated properties. Correlations of vapor-liquid equilibrium data for alcohol-containing syst ems by using van d