Graphene　has　been　attracting　great　interest　because　of　its　distinctive　band　structure　and　physical　properties.　The　study　of　graphene-based　composites　is　one　of　the　most　important　aspects.　In　this　paper,　a　coarse-grid　(CG)　beam　model　of　graphene　is　proposed　based　on　molecular　structural　mechanics　approach　and　energy　equivalence.　The　determination　of　the　Young＇s　modulus　and　geometrical　parameters　of　the　coarse　grid　of　graphene　are　described.　Then　the　continuum　model　for　graphene-based　composites　is　established　to　calculate　the　elastic　properties　of　the　composites.　The　covalent　bonds　between　carbon　atoms　found　in　graphene　are　simplified　to　the　coarse-grid　model　and　assigned　elastic　properties　using　beam　elements.　The　matrix　phase　is　modeled　as　a　continuum　medium　using　solid　elements.　The　connection　of　these　two　regions　is　assumed　to　be　bonded　perfectly.　Analysis　of　graphene-based　composites　having　single　layer　graphene　with　different　coarse　factors　are　performed.　Using　the　proposed　model,　the　deformations　obtained　from　the　simulation　are　used　to　predict　the　elastic　moduli　of　the　graphene-based　composites.　A　significant　enhancement　in　the　stiffness　of　the　graphene-based　composites　is　observed.　The　finite　element　results　are　in　an　acceptable　agreement.