Abstract: The second RFCC of Yanshan refinery is the only one FCC in which oxygen enrichment regeneration technology have been used at present in China. This article gives some analysis between conventional regeneration and oxygen enrichment regeneration. After adopting the oxygen enrichment regeneration technology, coke-burning was improved efficiently, and the equilibrium catalyst activity was enhanced. When the spent catalyst mix ratio was 75%, the regeneration carbon would decrease from 0.12% to 0.03%, equilibrium catalyst activity was 0.5 unit higher than conventional regeneration. The product distribution was optimized and the economic benefit of the FCC unit was increased. By using the technology, the cock-burning load and processing capability of the FCC unit could be greatly increased without changing the main blower and the regenerator structure. When the spent catalyst mix ratio was 75% , the coke burning intensity was 130.06 kg/(t·h)，7.73 kg/(t·h) higher than conventional regeneration .