In　this　study,　the　robustness　of　an　endogenous　partial-denitrification　(EPD)　system　was　demonstrated　during　a　105　days　operation　under　mainstream　conditions　at　low　temperature.　The　results　showed　a　high　nitrate-to-nitrite　transformation　ratio　(NTR)　of　88.7%,　a　suitable　NO2--N/NH4+-N　ratio　of　1.09,　and　no　residual　NO3--N　in　the　effluent,　as　reactor　temperature　was　decreased　from　25　degrees　C　to　13.5　degrees　C.　The　stable　morphology　of　the　EPD　granular　sludge　with　high　extracellular　polymeric　substance　content　(273.6-308.1　mg/g　VSS)　contributed　to　the　steady　performance　of　the　EPD　system.　Bath　tests　revealed　that　the　maximum　NTRs　(95.6%　and　96.3%)　were　slightly　higher　at　10　degrees　C　and　15　degrees　C　than　those　(90.4%　and　92.0%)　at　20　degrees　C　and　30　degrees　C,　resulting　from　the　lower　poly-beta-hydroxyvalerate　degradation　rate　or　the　negligible　denitrifying　dephosphatation　activity　at　low　temperatures.　Thus,　the　EPD　system　has　the　potential　to　provide　stable　nitrite　for　mainstream　anammox　at　low　temperature.