In　order　to　investigate　the　effect　of　organics　in　the　mature　landfill　leachate　on　the　Anammox　process　treating　mature　landfill　leachate,　a　combined　process　consisting　of　nitritation　sequencing　batch　reactor　(SBR)　and　anaerobic　ammonium　oxidation　sequencing　batch　reactor　(ASBR)　was　developed.　The　real　mature　landfill　leachate　with　ammonia　of　(2000±100)mg/L　and　COD　of　(2200±200)　mg/L　was　used　in　this　study.　After　100　days,　the　ratio　of　NO2-/NOx-　reached　95%　or　more　in　SBRni.　ASBR　was　acclimated　under　the　filling　mode　of　increasing　the　mature　landfill　leachate　gradually　to　supply　the　ammonia.　The　results　show　that　the　biodegradable　COD　is　increased　with　the　ratio　of　mature　landfill　leachate　in　the　filling　of　ASBR.　When　the　biodegradable　COD　in　the　filling　increases　to　150　mg/L,　nitrogen　loading　rate　(NLR)　of　ASBR　decreases　from　1.20　kg/(m3·d)　to　0.28　kg/(m3·d),　and　nitrogen　removal　rate　(NRR)　decreases　from　1.10　kg/(m3·d)　to　0.19　kg/(m3·d).　This　indicates　that　the　system　tends　to　collapse.　When　the　biodegradable　COD　decreases　to　50　mg/L,　the　maximum　NLR　and　NRR　increases　to　1.55　kg/(m3·d)　and　1.20　kg/(m3·d),　respectively,　which　indicates　that　the　activity　of　Anammox　is　recovered.　Besides,　the　quantitative　PCR(polymerase　chain　reaction)　shows　that　the　proportion　of　Anammox　in　the　bacteria　increases　to　1.94%　when　activity　of　Anammox　becteria　is　recovered.