To investigate the effect of COD,NO3--N and post-aerobic on denitrifying dephosphorization process,a lab experiment was carried out by using an anaerobic/anoxic sequencing batch reactor(A2SBR) for a long time.The results show that when the influent COD is between 200 to 250 mg/L and PO43--P is between 4 mg/L to 6 mg/L,the removal efficiency of anaerobic COD,anoxic PO43--P is 80% and 92%,respectively,and when the influent of NO3--N is 35 mg/L,the effluent PO43--P concentration is lowest(0.34 mg/L) and the removal efficiency of PO43--P is 98.4%.Post-aeration can effectively remove the residual phosphate and the removal efficiency of PO43--P is up to 99%,meanwhile,post-aeration can significantly improve the sludge settling characteristics.