In this study, sulfonated organosilane graphene oxide (SSiGO) was synthesized by grafting 3-mercaptopropyl trimethoxysilane (MTPS) with graphene oxide (GO) and follow-up oxidation with hydrogen peroxide. The SSiGO was introduced into sulfonated poly (phthalazinone ether ketone) (SPPEK) to obtain composite membranes (SSiGO/SPPEK), and the physicochemical and electrochemical properties were extensively investigated. The results show that this SSiGO/SPPEK composite membranes possess excellent thermal and dimensional stability and super high proton conductivity. The proton conductivity of 10% SSiGO composite membranes was improved greatly from 0.094 to 0.22 S/cm from 30 to 80 A degrees C, in contrast with the 0.089-0.17 S/cm from 30 to 80 A degrees C of Nafion 212, which indicates that the SSiGO/SPPEK composite membranes have tremendous promise for proton exchange membranes fuel cells.