The　study　on　substrate　inhibition　kinetics　in　Anammox-UASB　reactor　was　carried　out　treating　low　C/N　wastewater.　Haldane　model　was　researched　through　non-linear　fitting　to　represent　the　inhibition　caused　by　nitrite.　The　results　showed　that　Haldane　model　was　suitable　for　fitting　dynamics　model.　In　Haldane　model,　rmax　was　1.15　kg/(m3·d),　KS=9.31　mg/L,　KIH=476　mg/L.　On　condition　that　the　concentration　of　nitrite　was　66.57　mg/L,　substrate　conversion　rate　reached　the　highest　value　which　was　0.90　kg/(m3·d)　actually.　And　it　was　78.1%　of　the　highest　value　in　theory.　©　(2013)　Trans　Tech　Publications,　Switzerland.