Solvothermal　synthesis　is　an　important　technology　to　prepare　the　inorganic　matter.　In　this　investigation,　xylenewater-thermal　reaction　of　polypropylene　(PP),　styrene　(St),　and　maleic　anhydride　(MAH)　under　pressure　was　carried　out　to　prepare　grafting　polymers.　Infrared　(IR)　spectra　and　NMR　spectra　confirmed　that　MAH　and　St　were　successfully　grafted　onto　the　PP　backbones.　Through　differential　scanning　calorimetry　(DSC)　and　X-ray　analysis,　it　was　found　that　the　crystallinity　of　grafting　polymers　decreased　due　to　the　formation　of　side　chains.　Response　surface　methodology　(RSM)　was　applied　to　investigate　the　influence　of　various　factors　on　the　grafting　percentage.　The　predicted　results　coincided　well　with　the　experimental　values　at　optimum　reaction　conditions;　therefore,　the　response　model　was　adequate　to　reflect　the　expected　optimization.　(c)　2011　Wiley　Periodicals,　Inc.　Adv　Polym　Techn　32:　109117,　2012;　View　this　article　online　at　wileyonlinelibrary.com.　DOI　10.1002/adv.20242