An　ANAMMOX　biofilter　was　employed　to　investigate　the　effect　of　nitrite　on　total　nitrogen　(TN)　removal　rate.　The　results　showed　that　the　nitrite　concentration　influences　the　removal　of　TN　greatly;　the　rate　of　TN　removal　and　pH　increased　with　nitrite　concentration　rising.　To　raise　nitrite　concentration　furthermore,　both　TN　removal　rate　and　pH　decreased.　This　suggests　high　nitrite　concentration　would　inhibit　activity　of　ANAMMOX　bacteria.　Moreover,　the　data　indicated　that　the　proper　nitrite　concentration　should　be　84.4　mg/L　for　excellent　total　nitrogen　removal　effect.