Ethylene propylene diene methylene linkage rubber (EPDM)-clay hybrids have been prepared by mixing with EPDM and organophilic clay via vulcanization process. When we used thiuram and dithiocarbamate for the vulcanization accelerator, EPDM-clay hybrid was prepared successfully. In this EPDM-clay hybrid, the silicate layers of the clay were exfoliated and almost dispersed to the monolayers. The tensile strength of the EPDM-clay hybrid loading 4 wt% clay exhibited 2.0 times higher value compared to that of neat EPDM at 25 degreesC. The storage moduli (E') of the EPDM-clay hybrid were also higher than that of neat EPDM. The gas permeability of EPDM-clay hybrid decreased 30% as compared with neat EPDM.