A　novel　process　combined　simultaneous　partial　nitrification-anammox　(SPNA)　with　modified　denitrifying　phosphorus　removal　(DPR)　in　two　sequencing　batch　reactors　(terms　as　SPNA-SBR　and　mDPR-SBR)　was　proposed　for　treating　ammonia　(NH4+-N)　and　domestic　wastewaters.　Firstly,　NH4+-N　contained　wastewater　was　fed　into　SPNA-SBR　for　autotrophic　nitrogen　removal.　Meanwhile,　domestic　wastewater　was　introduced　to　mDPR-SBR　for　anaerobic　phosphorus　release　and　intracellular　carbon　storage.　Then,　nitrate　(NO3--N)　produced　in　SPNA-SBR　was　discharged　to　mDPR-SBR,　where　NO3--N　was　reduced　to　dinitrogen　gas　(N-2)　via　anoxic　denitrifying　phosphorus　removal.　Finally,　the　residual　NH4+-N　and　PO43--P　in　mDPR-SBR　were　removed　via　aerobic　simultaneous　nitrification,　endogenous　denitrification　and　phosphorus　removal　(SNEDPR).　The　long-term　operation　(235-day)　suggested　that　a　desirable　nutrient　removal　performance　was　achieved　in　the　SPNA-mDPR　process,　and　the　final　effluent　NH4+-N,　total　nitrogen　and　PO43--P　concentrations　were　1.5,　5.0　and　0.2　mg.L-1,　respectively.　In　the　SPNA-SBR,　SPNA　contributed　to　similar　to　90%　of　NH4+-N　removal　at　low　aeration　intensity　(dissolved　oxygen　(DO):　0.1　mg.L-1);　in　the　mDPR-SBR,　similar　to　70%　of　PO43--P　and　similar　to　100%　of　NO3--N　were　simultaneously　removed　via　anoxic　DPR,　and　post-aerobic　SNEDPR　further　reduced　similar　to　30%　of　PO43--P　and　similar　to　70%　of　NH4+-N.　Stoichiometry-based　microbial　activity　analysis　demonstrated　that,　in　the　mDPR-SBR,　high　activity　of　denitrifying　phosphorus　accumulating　organisms　(DPAOs)　over　denitrifying　glycogen　accumulating　organisms　(DGAOs)　in　anoxic　NO3--N　removal　(71.1%　＞　28.9%)　facilitated　DPR,　and　high　percentage　of　SNEDPR　via　nitrite　(89.6%)　over　nitrate　saved　52%　intracellular　carbon　demand　to　realize　the　deep-level　nutrient　removal　without　external　carbon　addition.