The applications of the solubility parameter in chemical, petroleum and polymer engineering industries have been cleared up along the past 50 years. In this article, the Hildebrand solubility parameter of over 250 substances were calculated by the modified ER (Esmaeilzadeh-Roshanfekr) equation of state and some others (the Peng-Robinson, Soave-Redlich-Kwong, Patel-Teja and Schmidt-Wenzel) and compared with the experimental data. Once the less average errors of the mER method predictions were satisfied in subcritical and some supercritical fluids region, a correlation based on this EOS was presented in order to calculate the total HSP (Hansen solubility parameter) of various types of organic components categorized in 13 distinct groups including paraffins, olefins, aromatics, naphthenes, alcohols, aldehydes, ketones, ethers, esters, amines, carboxylic acids and two petroleum sub-fractions (resins and asphaltenes). The optimal values of the model parameters were obtained applying the DE (differential evolution) optimization method. The absolute average deviations of the proposed correlations results from the experimental ones lied between 0.09 and 6%. (C) 2010 Elsevier B.V. All rights reserved.