The　vehicular　non-methane　volatile　organic　compounds　(NMVOCs)　emissions　were　estimated　in　2010　for　Beijing-Tianjin-Hebei　(BTH)　region,　China.　The　NMVOCs　emission　factors　of　passenger　cars　(PC),　light　duty　vehicle　(LDV),　buses　(BUS),　heavy　duty　trucks　(HDT)　and　motorcycles　(MC)　were　calculated　by　the　COPERT　IV　model.　The　total　NMVOCs　emissions　were　78.9x10(3)　t,　41.9x10(3)　t　and　139.8x10(3)　t　for　Beijing,　Tianjin　and　Hebei,　respectively.　PC　was　the　main　source　category　and　vehicles　with　gasoline　were　the　dominant　contributors　for　NMVOCs　emissions.　Inventory　for　detailed　NMVOCs　species　was　also　developed.　Results　showed　that　ethylene,　toluene,　benzene,　isopentane,　propene,　ethane,　m,p-xylene,　1,2,4-trimethylbenzene,　2-methylpentane　and　1-Butene　were　the　main　species.　Because　of　the　important　influences　on　ozone　formation,　the　ozone　formation　potentials　(OFP)　of　NMVOCs　were　further　calculated.　Alkene　and　benzenes,　such　as　ethylene,　propene,　m,p-xylene,　1,2,4-trimethylbenzene,　toluene,　1-Butene,　m-ethyltoluene,　o-Xylene,　2-Methyl-2-butene　and　1,3,5-Trimetylbenzene,　were　the　key　species　for　ozone　formation.　The　results　can　provide　scientific　support　for　mitigating　vehicular　emissions　and　improving　air　quality.