The methods of viscometry, isothermal diffusion, and high-speed sedimentation are used to study the structure, properties, and molecular characteristics of complexes formed by sulfonated polystyrene molecules containing 1.35 molar % ionogenic SO₃Na groups and molecules of a surfactant, bis(2-ethylhexyl) sodium sulfosuccinate, in m-xylene. It was found that, at molar ratio of ionomer to surfactant units equal to or smaller than 2.5, complexes with a limiting composition were formed in solution. In the process, micelles containing on average 15 surfactant molecules were formed on ionogenic groups of the ionomer; which is virtually equal to their aggregation number in m-xylene. The dimensions of such a complex are 1.18 times greater than those of a polystyrene molecule with the same degree of polymerization and 1.52 times greater than the dimensions of single molecules of the initial ionomer in m-xylene. The complexation was found to significantly weaken the association of the ionomer molecules. The exponent characterizing the dependence of the molecular mass of the associate on the solution concentration is almost four times smaller than that for the ionomer solution.