A method for predicting an analytical equation of state for polymer mixtures and blends from surface tension and liquid state density at normal (ordinary) temperature (γ n , ρ n ), as scaling constants, is presented. B 2 (T) follows a promising corresponding-states principle. Calculation of α(T) and b(T), the two other temperature-dependent constants of the equation of state, are made possible by scaling. As a result, γ n and ρ n are sufficient for determination of thermophysical properties of polymer mixtures and blends.We applied the procedure to predict liquid density of poly(ethylene glycol) (PEG-200)+1-octanol solutions and poly(propylene glycol) (PPG)+poly(ethylene glycol) (PEG-200) blends at compressed state with temperature range from 298.15 to 338.15 K and pressures up to 40 MPa. In this work, the ISM EoS is extended to polymer mixtures and blends as well as pure case without proposing any mixing rule.