In　this　study,　laboratory　scale　experiments　were　conducted　to　investigate　the　nitrogen　removal　from　pharmaceutical　manufacturing　wastewater.　The　results　indicate　that　by　selective　inhibition　of　free　ammonia　on　oxidizers,　nitrogen　removal　can　be　achieved　by　nitritation　and　denitritation　process.　The　nitrite　ratio　was　above　98%　in　the　aerobic　stage　and　the　nitrogen　removal　efficiency　was　about　99%.　The　complete　ammonia　removal　corresponded　exactly　to　the　＂Ammonia　Valley＂　in　the　pH　versus　time　graphic　and　the　anoxic　reaction　was　completed　when　the　＂Nitrite　Knee＂　appeared　in　the　ORP　versus　time　graphic.　Optimization　of　the　SBR　cycle　by　step-feed　and　on-line　control　with　pH　and　ORP　strategy　allowed　the　carbon　and　energy　saving.　The　easy　operation　and　the　low　cost　make　the　SBR　system　an　interesting　option　for　the　biological　nitrogen　removal　from　the　pharmaceutical　manufacturing　wastewater.