Maleic anhydride (MA) grafted ethylene-propylene-diene terpolymer (EPDM-g-MA) was prepared using both solution and reactive processes. The maleation of EPDM in the solution process was carried out using a benzoyl peroxide (BPO) initiator at 110℃ for 6 h. In the reactive process, the banbury-type internal mixer was used with dicumyl peroxide (DCP) as the initiator. The grafting rations of the MA on the EPDM relative to the MA and initiator contents were measured. The maximum grafting ratios were 2.4% and 1.4% in the solution and reactive processes, respectively when 10 phr of MA and 0.25 phr of the initiator were used. EPDM-g-MA was mixed with α,ω-aminopropyl polydimethylsiloxane using roll mill techniques at room temperature and imidized by aging at 240℃ for 2 h. The curing of the maleated EPDM/PDMS was confirmed by measuring the FT-IR and the morphology was obtained by SEM.