In　this　study,　a　coupled　MM5-CAMx　air　quality　modeling　system　is　proposed　for　simulating　the　PM10　(which　stands　for　the　suspended　particulate　matter　less　than　10　mu　m　in　diameter)　concentration　in　Beijing,　China.　The　PSAT　(particulate　matter　source　apportionment　technology)　technique　is　used　to　investigate　the　PM10　source　apportionment　in　this　area.　The　results　indicate　that　the　influence　from　regions　outside　of　Beijing　including　Hebei　province,　Shanxi　province,　Tianjin　city,　and　Inner　Mongolia　cannot　be　ignored,　and　the　total　emission　source　contribution　ratio　(ESCR)　from　these　regions　is　26.65%.　Emissions　from　four　local　industries　in　Beijing　including　stationary　emission　source,　road　dust　emission　source,　construction　sites　dust　emission　source,　and　fugitive　industrial　emission　source,　which　has　an　ESCR　of　59.59%,　are　main　local　contributors　of　PM10.　Further　analysis　shows　that　these　four　industry　emissions　located　in　the　urban　area　of　Beijing　are　main　contribution　sources　of　PM10　pollution　in　Beijing,　with　an　ESCR　of　51.67%.　The　results　obtained　can　provide　useful　information　for　Beijing＇s　PM10-emission　control　and　abatement.　They　can　also　be　used　for　further　pollution-mitigation　plans　establishment　and　providing　a　solid　support　for　sound　air　quality　management.