The phosphorous removal behaviors under higher and moderate organic loading and after different durations of anaerobic stages were studied in the reversed A2/O process. Under both loading, the length of anaerobic stages did not significantly affect the subsequent aerobic phosphorus uptake efficiencies. Under higher loading, the available carbon sources are adequate, prolonging anaerobic stages led to more released phosphorus from phosphate accumulating organisms (PAOs). However, the phosphorus uptake rate in aerobic stage was almost the same as that of lower loading. At an anaerobic reaction time of 2.0 h, the corresponding specific aerobic phosphorus uptake rate achieved the highest value (6.13 mg/(L.h)). These results can help to determine the anaerobic hydraulic retention time in the reversed A2/O process.