In　order　to　analyze　the　effect　of　salinity　on　NOB　(nitrite-oxidizing　bacteria)　activity　and　kinetic　characterization,　NOB　was　enriched　in　a　lab-scale　SBR　system　with　high　concentration　of　nitrite　wastewater　in　this　study.　The　FISH　(fluorescence　in　situ　hybridization)　analysis　showed　that　Nitrobacter　accounted　for(81%±6%)of　total　bacteria.　The　maximum　specific　nitrite　oxidation　rate　was　(42.5±0.9)mgN/(gVSS•h).　The　effect　of　salinity　on　NOB　activity　was　investigated　using　this　mixed　culture.　The　kinetic　parameters　of　NOB　(Ko,　KS)　were　both　measured　under　salinity　of　10g/L.　Results　showed　that　compared　with　salinity　0g/L,　the　activity　of　NOB　decreased　3.3%　unders　alinity　of　15g/L　and　decreased　11%　under　salinity　of　10,　20g/L.　When　salinity　was　10g/L,　the　maximum　specific　nitrite　oxidation　rate　was　(37.9±0.7)mgN/(gVSS•h).　The　half-saturation　constant　for　oxygen　(Ko)　and　nitrite　(KS)　were　(1.51±0.06),　(6.06±0.15)　mg/L.　The　values　of　Ko　and　KS　were　higher　than　recommended　value　of　ammonia-oxidizing　bacteria　(AOB)　in　ASM2model.　It　is　suggested　that　salinity　could　reduce　maximum　specific　nitrite　oxidation　rate　and　affect　the　oxygen　affinity　and　substrate　(nitrite)　affinity　of　NOB.　©　2020,　Editorial　Board　of　China　Environmental　Science.　All　right　reserved.