The performance of biological phosphorus removal (BPR) in a sequencing batch reactor (SBR) with single-stage oxic process was investigated using simulated municipal wastewater. The experimental results showed that BPR could be achieved in a SBR without anaerobic phase, which was conventionally considered as a key phase for BPR. Phosphorus (P) concentration 0.22-1.79 mg L-1 in effluent can be obtained after 4 h aeration when P concentration in influent was about 15-20 mg L-1, the dissolved oxygen (DO) was controlled at 3 +/- 0.2 mg L-1 during aerobic phase and pH was maintained 7 +/- 0.1, which indicated the efficiencies of P removal were achieved 90% above. Experimental results also showed that P was mainly stored in the form of intracellular storage of polyphosphate (poly-P), and about 207.235 mg phosphates have been removed by the discharge of rich-phosphorus sludge for each SBR cycle. However, the energy storage poly-beta-hydroxyalkanoates (PHA) was almost kept constant at a low level (5-6 mg L-1) during the process. Those results showed that phosphate could be transformed to poly-P with single-stage oxic process without PHA accumulation, and BPR could be realized in net phosphate removal. (C) 2007 Elsevier Ltd. All rights reserved.