Polypropylene-graft-polystyrene (PP-g- PS) was synthesized by the coupling reaction of brominated polypropylene produced by metallocene-catalyzed copolymerization of propylene with 11-bromo-1-undecene and polystyryl lithium salts made by living anionic polymerization, for the first time. These structures were confirmed by H-1 NMR analysis. TEM micrographs of PP-g- PS copolymers indicated the nanometer level microphase-separation morphology between the polypropylene segment and the polystyrene segment. Obtained PP-g- PS copolymers could work as an effective compatibilizer for PP and PS.