This　study　analyzes　the　impact　of　restriction　measures　on　urban　air　quality　during　the　post-Olympic　times　through　simulation　using　an　integrated　MM5-CMAQ　modeling　approach　under　emission　reduction　measure-scenarios　aimed　at　construction　works　and　traffic　activities.　Results　show　that　if　daily　vehicles　are　not　restricted,　the　mean　monthly　increase　ratios　of　PM10　concentration　are　6.81%,　8.27%,　and　7.85%　during　October,　November,　and　December　in　2008,　respectively;　and　the　mean　monthly　concentration　of　PM10　increases　by　6.88　μg/m3　in　October,　9.68　μg/m3　in　November,　and　12.10　μg/m3　in　December,　respectively.　Besides,　the　periods　of　November　2　to　6,　2005　and　December　25　to　29,　2007　are　selected　as　two　study　cases　with　heavy　pollution.　The　PM10　concentration　in　the　heavy　pollution　process　decreases　by　21.56%　in　November　and　20.30%　in　December　if　contingency　measures　are　conducted,　with　the　mean　concentration　of　PM10　decreasing　by　93.8　μg/m3　in　November　and　88.4　μg/m3　in　December,　respectively.　During　the　post-Olympic　times,　the　implementation　of　temporary　restrictions　on　main　local　emission　was　helpful　to　improve　the　air　quality　to　a　certain　extent　in　Beijing.　In　the　long　run,　the　long　term　regional　environmental　coordination　and　collaboration　mechanism　connected　with　systematic　measures　about　local　dominant　emission　reduction　is　the　key　to　deal　with　the　air　pollution　in　Beijing.