Abstract: A 500 kt/a RFCC unit was successfully revamped for energy conservation in CNOOC Zhongjie Petrochemical Co.in June, 2012. The technology overcame conventional contradiction between reaction temperature and catalyst/oil ratio, and has realized the idea of operating the FCC unit under low reaction temperature and large catalyst/oil ratio. The product quality and yield, energy consumption and flue gas emission are satisfied with the contract. An additional economic benefit of 62.1 million RMB is gained annually.