Taking　actual　domestic　wastewater　(C/N=2.6-4.1)　as　influent　substrate　and　polyurethane　filler　as　biological　carrier　(filling　rate　was　25%),　the　simultaneous　nitrification　and　denitrification　(SND)　was　achieved　in　sequencing　batch　biofilm　reactor　(SBBR)　in　a　short　period　of　time　(98　d)　with　gradually　increased　nitrogen　loading.　The　results　of　real-time　qualitative　polymerase　chain　reaction　(qPCR)　confirmed　the　enrichment　of　nitrifying　bacteria　in　the　reactor.　The　system　had　a　good　effect　of　organic　matter　and　nitrogen　removal　in　the　formal　running　period.　The　concentration　of　COD,　NH4+-N　and　TN　of　the　effluent　water　was　38.28　mgL-1,　1.23　mgL-1　and　8.23　mgL-1,　respectively.　Most　of　COD　was　taken　up　and　converted　to　polyhydroxyalkanoate　(PHA),　and　the　storage　products　were　used　for　denitrification,　which　removed　a　large　amount　of　nitrate.　The　removal　efficiency　of　TN　and　SND　was　calculated　as　82.95%　and　70.57%,　respectively,　and　the　NO2--Nconcentration　always　kept　low　level.　Since　the　nitrification　and　denitrification　reactions　took　place　in　the　same　reactor　and　conditions,　the　system　could　maintain　pH　in　a　steady　conditions　by　that　the　increasing　basicity　in　the　denitrification　process　can　complement　the　consuming　basicity　in　the　nitrification　process.　Furthermore,　the　reaction　time　can　be　effectively　controlled　and　the　power　consumption　can　be　decreased　through　the　curve　change　of　DO　and　pH　to　judge　the　operation　status　of　SND.　©　All　Right　Reserved.