text: A high concentration of biomass allows for microbes such as nitrifiers, denitrifiers, phosphorus accumulating organisms, and denitrifying phosphorus accumulating organisms to effectively treat domestic wastewater. Carbon source is of vital importance to biological phosphorus removal due to the availability of volatile fatty acids, which ultimately shape the compositions of phosphorus accumulating organisms. Recent studies revealed that adding glucose as a carbon source can reduce diversity in the microbial community. Glucose was more favorable for accumulation of nitrite oxidizing bacteria than Ammonia Oxidizing bacteria in contrast with sodium acetate. This study suggested that mixed carbon source by sodium acetate and glucose might act as a strategy to adjust the microbial community compositions within the simultaneous nitrification, denitrification and phosphorus removal system.