Expanding　a　high　level　of　openness　and　attracting　high-quality　foreign　direct　investment　(FDI)　while　preventing　foreign-invested　enterprises　from　relocating　to　host　countries　to　reduce　costs　and　circumvent　environmental　regulation　(ER)　in　their　home　countries,　which　can　transform　host　countries　into　＂pollution　heaven＂,　present　a　significant　challenge　for　emerging　markets　such　as　China.　Based　on　a　theoretical　analysis　that　integrates　various　frameworks,　this　study　constructs　a　panel　regression　model　to　empirically　investigate　the　relationship　between　ER　and　the　quality　of　FDI.　This　analysis　is　conducted　from　the　perspectives　of　administrative　means　and　market　mechanisms,　utilizing　panel　data　from　267　prefectural-level　cities　in　China　spanning　the　years　2005　to　2021.　This　study　reveals　the　following　conclusions:　(1)　The　implementation　of　ER　significantly　enhances　the　quality　of　FDI　within　cities,　a　conclusion　that　remains　robust　across　various　tests.　(2)　ER　improves　the　quality　of　FDI　through　two　key　pathways:　enhancing　green　competitiveness　and　fostering　green　technological　innovation.　(3)　In　comparison　to　the　isolated　effects　of　administrative　and　market　mechanism　policies,　the　synergistic　effect　of　these　two　approaches　proves　to　be　more　pronounced　in　elevating　the　quality　of　FDI.　(4)　ER　exerts　a　significant　impact　on　the　quality　of　FDI,　particularly　within　sub-samples　of　cities　characterized　by　higher　levels　of　environmental　protection　and　a　focus　on　non-resource-oriented　activities.　(5)　ER　has　a　negative　spatial　spillover　effect　on　FDI　quality.　This　study　serves　as　a　valuable　guide　for　emerging　markets　to　enhance　environmental　policy　effectiveness　and　assess　the　potential　for　a　new　open　economic　system.