A　modified　two-stage　partial　nitrification/anammox　(PN/A)　process　with　short　aerobic　HRT　of　5.7　h　was　established　and　realized　advanced　nitrogen　removal　from　domestic　wastewater.　The　first　process　was　partial　nitrification　in　the　PN-SBR,　the　initiation　and　stable　maintenance　of　partial　nitrification　was　achieved　by　preanaerobic　treatment　without　inoculation　or　addition　of　inhibitor,　nitrite　accumulation　rate　was　over　90%　and　maintained　over　200　days,　meanwhile　pre-anaerobic　improved　the　storage　of　endogenous　carbon　sources　to　enhance　the　nitrogen　removal　efficiency.　The　second　process　was　anammox　in　the　AMX-SBR,　which　was　fed　with　the　effluent　of　PN-SBR,　the　effluent　total　inorganic　nitrogen　was　below　5　mgN/L,　nitrogen　removal　efficiency　reached　92.06%.　Furthermore,　Candidatus-Brocadia　was　enriched　after　treating　domestic　sewage　with　low　ammonia　from　0.02%　to　0.23%.This　study　demonstrated　the　feasibility　of　starting　and　maintaining　partial　nitrification　by　pre-anaerobic　treatment　and　the　feasibility　of　nitrogen　removal　by　coupling　simultaneousnitrification-denitrification　with　anammox　to　treat　actual　municipal　sewage.