Considering　that　the　shapes　of　particles　have　an　important　impact　on　the　mechanical　properties　of　the　coarse　aggregate,　this　paper　proposes　a　new　method　for　characterizing　particle　shapes.　The　method　randomly　selects　a　series　of　points　on　ellipse;　then　those　points　are　connected　to　form　polygon　particles.　The　new　method　can　represent　more　types　of　particle　shapes　than　old　method　that　access　points　on　the　circle,　applies　more　broadly,　can　characterize　the　narrow　flat　particles.　In　addition,　a　new　algorithm　of　particle　delivery　is　proposed,　which　is　to　reduce　the　particle;　then　the　reduced　particles　are　put　to　the　given　area　randomly.　After　the　particle　was　meshed　by　triangular　element,　the　reduced　particles　was　enlarge　to　the　original　size.　Afterwards,　using　finite　combined　finite-discrete　element　method(FEM/DEM)　to　calculating　equilibrium　state,　a　sample　that　meet　given　void　ratio　was　generated.　Then　the　particle　generation　algorithm　above　and　FEM/DEM　was　combined,　the　FEM/DEM　method　is　applied　to　coarse　aggregate　numerical　simulation,　the　analysis　shows,　FEM/DEM　is　a　great　way　to　study　the　mechanical　properties　of　coarse　aggregate.　The　complex　particle　shape　can　also　be　modeling　simply,　because　the　particles　was　meshed　into　the　triangle　finite　element,　complex　contact　judgments　and　the　contact　force　calculation　can　be　transformed　into　a　standard　uniform　contact　judgments　and　contact　force　calculations　between　triangles,　all　calculations　can　be　standardization　and　unification.　At　the　same　time,　particles　can　be　deformed,　the　concept　of　stress　and　strain　that　belong　to　the　continuum　mechanics　was　still　retains,　rather　than　PFC　which　stress　and　strain　of　a　point　was　expressed　indirectly　by　the　measuring　circle.　Finally,　by　confined　compression　test　numerical　simulations　of　coarse　aggregate　show　enormous　potential　of　the　proposed　set　of　solutions　in　the　simulation　coarse　aggregate.　©,　2015,　Academia　Sinica.　All　right　reserved.