Abstract: It is well accepted that nitrogen and phosphorus are the predominant compounds for the promotion of algae growth, and the removal of nitrogen and phosphorus involved in the wastewater has received a world-wide attention. In the biological wastewater treatment process, temperature is one of the most important physical factors, which will influence the metabolic activity and growth of microorganisms and thus their conversion capabilities in the carbonaceous, nitrogen and phosphorus compounds. The effects of temperature variations on the removal efficiencies of chemical oxygen demand(COD), nitrogen and phosphorus were investigated with an anaerobic-aerobic-anoxic process(AOA)(i.e., modified A²/O process). Compared to the conventional anaerobic-anoxic-aerobic process(i.e., A²/O process), the modified A²/O process could utilize the internal carbon contained in poly-β-hydroxybutyric acid(PHB) of the phosphorus accumulation organisms(PAOs) as the carbon source in the anoxic stage for denitrification. The AOA process could avoid the problem induced by the lack of carbon source in denitrification and the completion of carbon source between microorganisms for nitrogen and phosphorus removal. Besides, the environmental conditions created under the AOA process could promote the reproduction and growth of the denitrifying phosphorus accumulation organisms(DPAOs). The effects of temperature variations on PHB degradation rate, NO-