This　paper　aims　to　study　the　vehicular　emissions　trends　in　the　Beijing-Tianjin-Hebei　(BTH)　region,　located　in　northern　China.　The　multiyear　emission　inventories　of　NOx,　CO,　VOC　and　PM10　from　road　vehicles　in　the　period　1999-2010　were　developed　by　the　COPERT　IV　model.　Results　show　that　vehicular　emissions　of　CO　and　VOC　have　decreased　by　annual　average　change　rates　(AACR)　of　-3.1%　to　-5.2%　and　-4.4%　to　-6.9%　in　the　study　area,　respectively.　However,　due　to　the　rapid　development　of　freight　traffic,　emissions　of　NOx　and　PM10　have　kept　increasing　in　Tianjin　and　Hebei.　Based　on　the　vehicular　emission　inventories,　trends　of　emission　levels　for　vehicles　with　different　standards,　as　well　as　the　overall　effects　of　implementing　vehicular　emission　mitigation　strategies　were　assessed.　It　is　suggested　that　passenger　cars　(PC)　with　Euro　0　and　Euro　I　standards,　which　were　at　higher　emission　level　in　the　PC　fleet,　should　be　gradually　eliminated.　Although　the　increasing　rates　(IR)　of　emissions　from　PC　were　lower　than　those　of　the　PC　population,　the　sharp　growth　of　PC　population　in　recent　years　contributed　to　a　remarkable　increase　of　emissions,　weakening　the　overall　mitigation　effect.　Total　vehicle　population　capacity　and　other　mitigation　measures　should　be　studied　in　China　in　order　to　develop　new　and　more　effective　vehicular　emission　control　strategies.　(C)　2012　Elsevier　Ltd.　All　rights　reserved.