Supermolecular structure of isotactic polypropylene/wollastonite/styrenic rubber block copolymers composites were studied as a function of elastomeric poly(styrene-b-ethylene-co-butylene-b-styrene) triblock copolymer (SEBS) and the SEBS grafted with maleic anhydride (SEBS-g-MA) content (from 0 to 20 vol%) by optical, scanning, and transmission electron microscopy, wide-angle X-ray diffraction and differential scanning calorimetry. Wollastonite particles disturbed the spherulitization of polypropylene matrix. Both elastomers affected the crystallization of polypropylene matrix mainly by solidification effect. Although SEBS-g-MA encapsulated wollastonite particles more expressive than SEBS forming thus core-shell morphology in higher extent, scanning electron micrographs indicated more constrained wollastonite particles in fractured surfaces of composites with SEBS elastomer. Moreover, SEBS-g-MA disorientated wollastonite particles and affected reorientation of the polypropylene crystallites stronger than SEBS elastomer. POLYM. ENG. SCI., 47:2145-2154, 2007. (C) 2007 Society of Plastics Engineers.