The present invention relates to a catalyst system, to a method of manufacturing this system, and also to uses of this system. The catalyst system of the invention is characterized in that it comprises molecules of a polymer having, at one of its ends or along the chain, one or more polar functional groups; a solvent, said solvent, due to the fact of said polar functional group of said polymer, provoking and maintaining, when said molecules of the polymer are introduced thereinto, an organization of said molecules of the polymer into aggregates, micelles or vesicles so that the polar functional groups of said polymer are located inside the aggregates, micelles or vesicles formed; and a catalyst activator and a catalyst trapped in said aggregates, micelles or vesicles of said polymer. The catalyst system of the present invention may be used, for example, for catalyzing a (co)polymerization of olefins.