Saline　old　landfill　leachate　was　treated　via　nitrite　using　an　up-flow　anaerobic　sludge　blanket　(UASB)　combining　with　an　anoxic/aerobic　(A/O)　reactor.　The　influence　of　salinity　shocks　from　10　to　35　g/L　on　the　performance　of　the　system　and　the　characteristics　of　the　activated　sludge　were　studied.　Results　indicate　that　the　combined　system　exhibits　certain　resistance　to　the　salinity　shocks　when　salinity　ranges　from　10　to　20　g/L.　With　the　further　increase　of　salinity　load　to　35g/L,　the　ammonia　and　total　nitrogen　removal　rates　reduce　to　83.9%　and　68.4%,　respectively,　while　the　removal　rate　of　organic　matter　still　remains　at　90.1%.　MLSS　(mixed　liquid　suspended　solids)　of　aerobic　sludge　decrease　from　4　129　to　3836　mg/L　and　the　SVI(sludge　volume　index)　of　aerobic　sludge　varies　from　91　to　119　mL/g,　while　anaerobic　sludge　in　UASB　presents　strong　salinity　shock　resistance.　Compared　to　dissolved　oxygen,　taking　pH　value　as　the　fuzzy-control　parameter　in　A/O　reactor　treating　landfill　leachate　containing　saline　is　a　better　choice.　The　nitrite　accumulation　rate　of　the　effluent　exhibits　small　range　of　ascension　under　the　dual　inhibitions　of　salinity　and　free　ammonia.