Characteristics　of　submicron　particulate　matter,　including　its　components,　during　December　5-30,　2016,　were　comprehensively　investigated　in　Beijing.　The　surface　transport　flux　was　calculated　as　well　as　the　cross-border　transport　influence　of　Beijing　and　the　North　China　Plain　(NCP)　on　Beijing　University　of　Technology　(BJUT)　based　on　the　non-refractory　submicron　particles　(NR-PM1)　and　species,　PM2.5,　and　gaseous　pollutant　observations,　together　with　wind　vectors.　The　Weather　Research　&　Forecasting　(WRF)　and　Comprehensive　Air　Quality　Model　with　Extension　(CAMx)　were　applied　to　demonstrate　the　vertical　PM2.5　flux　distribution.　These　results　showed　that　the　monthly　average　concentration　of　NR-PM1　was　86.1　+/-　86.5　mu　g　m(-3),　with　organics　forming　the　major　fraction　(49.2　+/-　11.1%),　followed　by　NO3-　(19.1　+/-　6.3%),　SO42-　(15.8　+/-　6.4%),　NH4+　(10.8　+/-　2.6%),　and　Cl　(5.1　+/-　2.9%).　The　accumulation　and　dissipation　of　pollutants　were　related　to　the　wind　vector,　with　higher　concentrations　in　the　southern　and　eastern　directions　with　low　wind　speed　(WS),　and　lower　concentrations　in　the　northwestern　direction　with　high　WS.　The　net　flux　intensities　were　stronger　from　WB　to　BJUT　for　particulate　matter　and　species,　from　EB　to　BJUT　for　gaseous　pollutants　and　from　NB　to　BJUT　for　all　pollutants,　which　might　attribute　to　the　mutual　influence　of　the　pollutant　concentration　and　wind　vector.　All　the　pollutant　flux　intensities　were　generally　stronger　in　the　heavy　pollution　episodes　(HPEs)　and　red　alert　episodes　(RAEs)　than　those　in　the　non-polluted　episodes　(NPEs).　Moreover,　the　PM2.5　net　flux　varied　with　the　height;　the　maximum　total　net　flux　occurred　at　a　height　of　252　m.　The　variations　in　PM2.5　flux　at　the　high-altitude　layer　were　similar　to　those　at　the　low-altitude　layer,　in　which　the　former　was　approximately　1.5-2　times　the　latter.　Furthermore,　the　external　transport　could　exert　important　influence　before　reaching　the　most　severe　stage　of　pollution,　while　the　local　emissions　had　a　greater　potential　to　form　heavy　pollution　extremes.　Overall,　the　aforementioned　results　could　provide　the　scientific　support　for　proposing　effective　joint　control　measures　and　mitigating　the　adverse　effects　of　heavy　pollution　in　NCP.