To　understand　the　impacts　of　different　combinations　of　planetary　boundary　layer　(PBL),　short-wave　(SW)　and　long-wave　(LW)　radiation　schemes　on　the　simulation　results　of　meteorological　variables　and　PM2.5　concentrations　under　extremely　heavy　pollution　conditions,　the　Weather　Research　and　Forecasting　model　with　Chemistry　(WRF-Chem)　model　was　applied　in　Beijing　to　investigate　a　high　PM2.5　pollution　episode　that　occurred　in　January,　2013.　Four　PBL　schemes,　two　SW　schemes　and　three　LW　schemes　with　a　total　of　12　ensemble　experiments　were　conducted　in　this　study.　The　simulated　meteorological　variables　including　the　temperature　at　2　m　(T2),　the　wind　speed　at　10　m　(WS10)　and　the　relative　humidity　(RH)　were　compared　with　their　actual　observations　and　the　PM2.5　concentrations.　A　correlation　analysis　between　the　PM2.5　and　T2,　WS10　and　RH　values　was　also　explored.　The　results　indicated　that　there　were　no　ideal　scheme　combinations　that　were　most　suitable　for　all　meteorological　variable　simulations　during　this　heavy　pollution　episode　in　Beijing.　With　the　same　emissions　input,　the　simulation　results　of　the　WRF-Chem　model　that　were　configured　with　different　physical　parameterization　schemes　may　vary　significantly.　As　for　the　PM2.5　simulation,　the　combination　of　the　YSU　PBL,　Goddard　SW　and　GFDL　LW　schemes　showed　the　greatest　consistency　with　the　observed　values.　Although　the　PBL　schemes　have　the　dominant　impacts　on　the　simulations　of　meteorological　variables,　the　selection　of　LW　and　SW　schemes　is　of　the　same　importance.