Anaerobic granular sludge was inoculated to an aerobic SBR, where CH3COONa was used as the carbon source. Observations on the change of granules' shape and structure revealed that the granules experienced a shape-keeping and component-replacing process. The sludge concentration increased at first 4 weeks and then decreased to reach a constant of 5g/L at 35d with its SVI of 30 - 40mL/g. Granular sludge dominated in the reactor and suspended sludge concentration was less than 0.5g/L during the end of the process. Anaerobic granular sludge, in which spheral bacteria was the main microorganism, was successfully developed to aerobic granular sludge in which filamentous and bacillius bacteria were the dominant microorganism.