By　combining　the　strong　and　light　carbon　fibers　(CFs)　with　polymers,　composite　materials　with　extraordinary　mechanical　properties　are　achieved.　However,　the　mechanical　properties　of　the　as-prepared　CF-reinforced　polymer　composites　can　not　satisfy　the　applications　in　certain　fields,　especially　for　the　poor　interactions　between　CFs　and　the　polymers.　To　enhance　the　mechanical　properties　of　composite　materials,　a　solid　phase　grafting　method　has　been　developed　to　improve　the　adhesion　forces　between　CFs　and　the　polymer,　by　modifying　the　surfaces　of　CFs.　The　effects　of　the　reaction　temperature,　reaction　time,　as　well　as　the　dosage　of　the　initiator　and　maleic　anhydride　(MAH)　on　the　grafting　efficiency　have　been　investigated　systematically.　The　structure　and　the　surface　chemistry　of　functionalized　CFs　have　been　characterized　by　Fourier　Transform　Infrared　(FT-IR),　Scanning　Electron　Microscope　(SEM),　X-ray　Photoelectron　Spectroscopy　(XPS),　Thermogravimetric　(TG),　and　contact　angle　test.　All　of　these　results　demonstrate　that　MAH　is　grafted　onto　the　surface　of　CFs　successfully　by　the　solid　phase　grafting　method.　The　MAH　grafted　CFs　significantly　improve　its　wettability,　which　further　improves　the　interfacial　adhesion　between　CFs　and　the　polymeric　matrix.　The　optimal　reaction　conditions　are　determined,　such　as　the　MAH/CF　molar　ratio,　the　dosage　of　initiator,　the　reaction　temperature　and　the　reaction　time　to　be　3/1,　2%,　90　degrees　C　and　4　h,　respectively.　These　attractive　interfacial　characteristics　of　modified　CFs　suggest　that　the　method　proposed　herein　is　a　novel　and　efficient　approach　to　develop　CF-reinforced　polymer　composites　with　outstanding　mechanical　properties　for　cutting-edge　industrial　applications.