Na montmorillonite (MT) was intercalated with the yellow dextrin plasticized with glycerol and used as a filler (1-4% by mass) for manufg. styrene-butadiene-styrene copolymer and dynamically crosslinked polypropylene/ethylene-propylene-diene blend matrix composites. For comparison, a com. amminium salt-modified MT was also used as a filler (up to 5% by mass). The composites reinforced with the dextrin-modified MT showed higher tensile strength and elongation at break than those reinforced with the com. modified MT In some cases, exfoliated systems were formed.