Nitrogen　removal　from　hypersaline　wastewater　was　successfully　started　up　by　inoculating　estuarine　sediments　for　140　days.　Efficient　ammonia　and　total　nitrogen　removal　was　sustained　under　specific　ammonia　loading　of　0.016-0.139　kg　N/[kg　VSS　day]　in　a　sequencing　batch　reactor.　Stable　nitrite　accumulation　was　observed　during　nitrification.　The　specific　ammonia　consumption　rate　was　higher　than　the　value　of　freshwater　activated　sludge　and　salt-acclimated　freshwater　activated　sludge.　With　methanol　as　carbon　source,　specific　nitrite　reduction　rate　of　halophilic　denitrifiers　was　much　less　than　the　freshwater　counterpart.　Halophilic　activated　sludge　was　characterized　as　good　settling　and　flocculation　prosperity　with　small　floc　size　and　net-like　sludge　structure.　The　abundance　of　ammonia-oxidizing　bacteria　outnumbered　ammonia-oxidizing　archaeas　in　both　estuarine　sediments　and　the　activated　sludge.　Nitrifier　population　was　dominated　by　the　halophilic　members　of　genus　Nitrosomonas.　This　study　demonstrated　the　application　of　mixed　halophilic　consortia　for　efficient　nitrogen　removal,　overcoming　the　limits　and　difficulties　of　applying　freshwater　bacteria　for　saline　wastewater　treatment.