Abstract: In this study, low-strength municipal wastewater was used to cultivate aerobic granular sludge in a pilot-scale sequencing batch reactor (SBR). During the granulation process, the characteristics of the sludge were investigated, and the operation parameters such as settling time and volume exchange ratio were adjusted and optimized according to the characteristics of sludge in the reactor to cultivate high-powered and stable aerobic granular sludge. The granules with small size were observed in the reactor after 40 days’ cultivation. After 160 days’ cultivation, the granules became mature. Their maximum size reached 0.8 mm, and a mass of protozoa appeared around the granules. In the course of granulation, the specific gravity, settling velocity, and mixed liquor suspended solids (MLSS) mass concentration increased from 1.004 0 g/cm³, 6.8 m/h and 4 000 mg/L at the initial stage to 1.010 5 g/cm³, 38.5 m/h and 8 000 mg/L, respectively, while the sludge volumetric index (SVI₃₀) decreased from 75 mL/g to 40 mL/g. The concentrations of COD_Cr and NH₄⁺-N in the effluent from the granular reactor were below 50 and 5 mg/L, respectively, indicating high removal efficiencies of COD_Cr and NH₄⁺-N by the aerobic granular sludge.