In　this　study,　an　advanced　transport　flux　method　based　on　the　comprehensive　stereoscopic　observation　verification　was　used　to　evaluate　the　contribution　of　transport　to　pollution　in　the　North　China　Plain　(NCP)　and　Sichuan　Basin　(SCB).　The　simulations　were　verified　using　fixed-point　lidar　and　satellite　observations,　and　the　results　demonstrated　that　the　modeling　flux　calculation　method　was　suitable　for　investigating　the　evolutionary　trend　of　PM2.5　flux.　The　monthly　inflow,　outflow,　and　net　flux　indicated　the　intensive　interactions　and　significant　temporal　and　spatial　variations　of　PM2.5　transport　though　the　boundary　segment　of　the　city　and　region.　In　both　autumn　and　winter,　the　Beijing-Tianjin-Hebei　(BTH)　region　always　played　the　role　of　＂source　＂　region,　while　Cheng-Yu　(CY)　region　principally　acted　as　a　＂convergence　＂　region.　In　autumn　and　winter,　the　BTH　region　was　controlled　by　a　cold　front　weather　system,　and　the　pollutants　were　readily　transported　to　the　surrounding　areas.　However,　the　CY　region　was　affected　by　the　complex　terrain,　with　small　wind　speeds　near　the　ground　and　poor　horizontal　diffusion.　The　upper　air　was　controlled　by　the　northwestern　winds　behind　the　trough,　and　the　air　subsidence　is　substantial.　The　combined　action　of　horizontal　and　vertical　wind　directions　caused　the　accumulation　of　pollutants　in　the　basin.　Notably,　one　intrinsic　transport　pathway　during　two　representative　months　was　identified　based　on　the　investigation　of　cross-city　and　cross-region　transport,　namely　the　southwest-northeast　(SW-NE)　pathway　in　the　BTH　region.　In　the　CY　region,　the　northeastern　transport　pathway　greatly　influenced　the　cities　in　the　basin.　Additionally,　through　the　analysis　of　the　typical　heavy　pollution　processes　in　the　two　regions,　it　was　found　that　the　southwest　pathway　of　the　BTH　region　and　northeast　pathway　of　the　CY　region　in　inter-city　transport　were　significant　factors　before　reaching　the　most　severe　stage　of　pollution.