AbstractThe previously deduced four‐parameter equation of state for melts of linear polymers was reduced to a three‐parameter form, consistent with the theorem of corresponding states. The methods of determining the characteristic parameters of the new and the previous equation are given. The characteristic parameters for polystyrene, poly(o‐methylstyrene), poly(vinyl acetate), linear polyethylene, isotactic polypropylene and poly(butyl methacrylate) are calculated, using the experimentalpVTdata from literature. The dependence of the characteristic pressure on the temperature, observed in the case of poly(butyl methacrylate) is explained in terms of bending of the valency angle at the —CH2‐group in the backbone, due to strong steric hindrances in vinylide