Graphene,　as　a　rising-star　materials,　has　attracted　interest　in　fabricating　lightweight　self-lubricating　metal　matrix　composites　with　superior　mechanical　and　wear　properties.　In　this　work,　graphene　nanoplatelets　(GNPs)　reinforced　AZ31　alloy　composites　were　fabricated　by　a　powder　metallurgy　technique　and　then　a　hot　extrusion.　The　effects　of　GNPs　content　(0.5,　1.0,　and　2.0　wt.%)　on　the　microstructures,　mechanical　properties,　and　wear　performance　of　the　extruded　GNPs/AZ31　composites　were　studied.　It　was　found　that　the　addition　of　GNPs　resulted　in　a　weakened　basal　plane　texture　and　grain　refinement　of　the　AZ31　matrix　metal.　Less　than　1.0　wt.%　GNPs　in　GNPs/AZ31　composites　resulted　in　the　enhancement　in　both　Vickers　hardness　and　tensile　yield　strength　with　acceptable　elongation.　The　Vickers　hardness　and　tensile　yield　strength　of　1.0GNPs/AZ31　composite　increased　by　4.9%　and　9.5%　respectively,　compared　with　the　unreinforced　AZ31.　Moreover,　the　elongation　of　the　composites　was　about　the　same　as　the　AZ31　base　alloy.　Both　the　friction　coefficient　and　the　wear　mass　loss　continuously　decreased　with　the　increasing　GNPs　content,　which　exhibited　a　self-lubricating　effect.　The　relationship　of　the　friction　coefficient　and　wear　mass　loss　with　the　GNPs　content　could　be　modeled　in　terms　of　the　Holliday　model　and　the　exponential　decay　model,　respectively.　The　worn　surface　morphology　revealed　that　adhesive　wear　and　abrasive　wear　simultaneously　acted　in　AZ31　alloy.　Nevertheless,　abrasive　wear　became　the　dominant　wear　mechanism　in　the　GNPs/AZ31　composites.