The study on physicochemical properties of maltodextrin-coated cerium oxide nanoparticles was carried out. The surface structure and properties of CeO2 nanoparticles were investigated. The ability of CeO2 nanoparticles to perform the functions of catalase and peroxidase enzymes, as well as to inactivate hydroxyl radicals was shown. Keywords: nanoparticles, cerium oxide, catalytic activity, antioxidant activity.