The　interface　between　nanocatalysts　and　graphene　oxide　(GO)　has　been　found　to　play　a　crucial　role　in　enhancing　the　catalytic　activity　and　improving　the　selectivity　of　amination　reactions　in　N,N-dimethylformamide　(DMF).　The　composite　catalysts　of　CuO/GO　used　for　the　catalytic　coupling　of　aryl　halides　with　amines　in　DMF　can　completely　inhibit　the　side　reaction　between　the　aryl　halides　and　fragments　of　DMF.　With　identical　amounts　of　Cu-catalysts,　the　conversion　of　iodobenzene　and　the　selectivity　for　the　target　product　reached　100%　when　CuO/GO　composite　catalysts　were　employed,　while　these　results　were　70.3　and　42.8%,　respectively,　when　CuO　catalysts　were　used　alone.　Experimental　evidence　confirms　that　the　interfacial　effect　of　CuO/GO　is　the　origination　of　the　improved　performance　of　composite　catalysts,　which　has　been　found　to　efficiently　transfer　fragments　of　DMF　to　GO　and　avoid　unexpected　side　reactions　during　the　catalytic　process.