In　this　paper,　the　mechanical　behaviour　of　graphene/aluminum　multilayered　nanocomposites　(GAMC)　was　studied　by　conducting　the　nanoindentation　simulations　using　molecular　dynamics　(MD)　method.　The　reinforcement　effect　of　graphene　on　aluminum　was　investigated　by　two　different　cases:　the　graphene　layers　are　considered　as　the　reinforcement　and　the　coating　materials　respectively.　The　microscopic　deformation　mechanism　is　investigated　through　the　study　of　a　hemispherical　diamond　indenter　indenting　against　the　monocrystalline　Al　and　GAMC.　For　the　graphene-coated　Al　composite　(GCA),　it　is　found　that　graphene　coating　layers　have　an　effect　on　the　characteristics　of　dislocation　slip　in　Al　matrix　and　improve　the　load　carrying　capacity　of　the　GCA　significantly.　In　addition,　graphene-reinforced　Al　composite　(GRA)　with　different　spacing-distance　of　the　graphene　layers　was　investigated.　It　is　concluded　that　the　GRA　shows　an　increasing　nanoindentation　properties　with　reducing　the　thickness　of　Al　layers.　Although　the　present　research　is　based　on　monocrystalline　aluminum,　the　deformation　mechanism　here　can　be　applied　to　other　face-centered-cubic　(FCC)　monocrystalline　metals　structures.　©　Published　under　licence　by　IOP　Publishing　Ltd.