The　effects　of　four　factors,　including　NaCl　concentration,　aeration　time,　chemical　oxygen　demand　(CODCr)　and　influent　NH4+-N　concentration,　on　partial　nitrification　and　denitrification　by　aerobic　granular　sludge　(AGS)　were　investigated　using　a　sequencing　batch　reactor　(SBR).　The　results　showed　that　when　the　five　factors　were　20　g/L,　8　h,　600　mg/L　and　70　mg/L,　respectively,　the　nitrite　accumulation　rate　(NAR)　and　the　NH4+-N　removal　rate　achieved　their　highest　points　under　the　conditions　of　pH,　temperature　and　dissolved　oxygen　(DO)　concentration　being　8.0,　30　and　3　mg/L,　respectively.　When　influent　NaCl　concentration　was　10　g/L,　nitrite　oxidizing　bacteria　(NOB)　was　completely　suppressed,　but　ammonia　oxidizing　bacteria　(AOB)　maintained　normal　activity.　The　high　CODCr　concentration　improved　NAR.　NaCl　threshold　of　partial　nitrification　and　denitrification　by　AGS　was　up　to　50　g/L,　while　the　NH4+-N　removal　rate　was　less　than　50%　at　this　point.　This　indicates　that　AOB　was　severely　inhibited,　and　AGS　lost　the　capability　of　partial　nitrification.　AGS　had　obvious　simultaneous　nitrification　and　denitrification　(SND).　The　average　SND　rate　and　specific　SND　rate　were　24.2%　and　0.63　h-1　respectively.　More　obvious　SND　effects　were　favored　by　low　DO　than　high　DO.　©,　2015,　Editorial　department　of　Molecular　Catalysis.　All　right　reserved.