Construction　of　graphene-based　nanocomposite　system　is　an　effective　approach　for　the　expansion　and　enhancement　of　applications　of　graphene.　Owing　to　the　synergy　effect　of　different　constituents,　the　electrical,　chemical　and　electrochemical　properties　of　graphene　can　be　greatly　improved,　leading　to　the　expansion　and　enhancement　of　the　electrochemical　effects　of　graphene.　Graphene　nanocomposites　provide　a　novel　and　efficient　electrochemical　platform　for　the　immobilization　of　oxidoreductase　and　the　realization　of　direct　electrochemistry,　which　can　apply　in　the　design　and　preparation　of　third-generation　electrochemical　biosensors,　showing　excellent　sensitivity　and　selectivity　towards　the　detection　of　glucose,　cholesterol,　Hb,　DNA,　H2O2,　O-2　and　small　biomolecules.　This　paper　reviews　the　progress　of　graphene　nanocomposites　applying　in　electrochemical　biosensors,　including　the　nanocomposites　of　graphene　with　precious　metal,　metal　oxide/semiconductor　nanoparticle,　polymer,　dye　molecule,　ionic　liquid　and　biomolecule.　The　future　development　and　application　prospect　of　graphene　in　electrochemical　fields　are　also　discussed.