The work summarizes the data of studies on the effect of nanofiller additives containing copper oxide nanoparticles stabilized by a high-pressure polyethylene matrix obtained by the mechanochemical method on the physico-mechanical, rheological properties and crystallization of thermoplastic mixed elastomers on the basis of isotactic polypropylene and ethylene propylene diene rubber. The prospects of using this additives to indicated elastomers that provides to the creation of a fine-spherical layered structure of the composition, characterized by improved melt flow rates, rheological, physicomechanical properties, and thereby expand the scope of application obtained nanocomposites.