Effects of Staphylococcus saprophyticus CGMCC 3475 as starter culture on lipolysis-oxidation and quality of fermented pork loin during processing(fermented for 30d,50d,70d,90d and 110d) were studied,with non-inoculated pork loin as control.Lipolysis-oxidation and its correlation during fermenting were studied by analyzing free fatty acids(FFA),thiobarbituric acid(TABRS),diene value and carbonyl value.Volatile flavor compounds such as aldehydes and ketons were also studied.The results showed that the content of SFA,MUFA and PUFA of the inoculated pork loin increased significantly(P<0.05) than that of in the non-inoculation during fermenting except at 50 days.Content of SFA and PUFA of both samples reached highest value at 90 days,and content of MUFA increased throughout the fermenting.TBARS value decreased throughout the fermenting but increased at 70 days.Carbonyl value and diene value increased during fermenting,and both values of the inoculation were higher significantly(P<0.05) than the non-inoculation.Compared to control fermented pork loin,less linear chain aldehydes and ketons but 56.7% esters were detected in the inoculated pork loin at 70 days,while the content of linear chain aldehydes and ketons were significantly higher(P<0.05) during other fermenting stages.