The　grafting　polymerization　of　maleic　anhydride　(MAH)　and　styrene　(St)　onto　PP　was　carried　out　in　suspension　phase.　Infrared　(IR)　spectra　and　1H-NMR　spectra　confirmed　that　MAH　and　St　were　successfully　grafted　onto　the　PP　backbone.　The　influences,　such　as　monomers　concentration,　reaction　temperature,　initiator　concentration　and　reaction　time,　on　the　grafting　polymerization　rate　were　also　studied,　and　then　the　polymerization　model　was　obtained　to　describe　the　polymerization　regularities.　The　results　showed　that　the　model　was　adequate　to　reflect　the　courses,　and　diffusion　and　equilibrium　adsorption　played　an　important　role　in　suspension　polymerization　©　Springer-Verlag　2009.