Modern methods for determining the surface free energy and their parameters were analyzed in the context of the presented investigations. The method of Berger and van Oss-Chaudhury-Good were found as the most suitable method for the determination of wetting solid polymer surfaces. Methods of nonlinear systems by Della Volpe and Siboni were evaluated and adapted. Various data of the surface free energy as well as its components have been identified for a number of polymer surfaces by application of spatial equation solutions.