To　enhance　the　simultaneous　removal　of　nitrogen　(N)　and　phosphorus　(P)　of　low　C/N(P)　ratio　sewage　by　A2/O　technique,　and　ensure　the　effluent　meet　the　first　class　level　A　standard　of　GB18918-2002,　two　patterns　of　A2/O　technique　were　conducted　to　treat　the　experimental　sewage.　Pattern　1　was　the　A2/O　technique　with　the　carrier,　under　the　optimized　conditions　of　tHR=8.2　h,　R=80%,　r=250%-300%,　ρ(DO)=1.5-0.5　mg/L,　the　concentration　of　TP　in　effluent　of　the　system　still　exceeded　the　standard.　Pattern　2　was　the　improved　pattern　1-terminal　intermittent　aeration　A2/O　technique　with　the　carrier,　which　contained　an　intermittent　aeration　zone　following　the　aerobic　zone,　meanwhile,　the　approaches　of　sludge　return　and　discharge　were　changed.　The　novel　system　with　the　long　tSR　of　22.3　d　ran　at　the　conditions　of　the　optimal　operating　modes　above-mentioned　for　A2/O　zone,　tHR=4　h　for　the　intermittent　aeration　zone,　and　the　aeration　cycle　was　1　h:　aeration　time　was　1　min　(ρ(DO)=0.3-0.5　mg/L)and　settling　time　was　59　min.　The　operational　results　showed　that　the　average　removal　rate　of　COD,　NH4+-N,　TP　and　TN　reached　87.8%,　99.1%,　95.5%　and　90.8%,　respectively.　The　nitrosation　rate　of　the　effluent　was　above　70%,　and　DPAO/PAO　ratio　in　sludge　was　95.65%,　the　final　effluent　of　the　system　met　the　first　class　level　A　of　the　national　standard　through　the　pathway　of　shortcut　nitrification　and　denitrifying　nitrogen　and　phosphorus　removal.　©,　2015,　Harbin　Institute　of　Technology.　All　right　reserved.