Abstract: In the test group,fresh leg of Tan mutton was frozen in still air at- 60 ℃,then thawed in still air under different temperatures at 25,10 and 5 ℃.The control group was chilled at 3 ℃,24 h.Volatile flavor compounds were measured by solid phase microextraction- gas chromatography- mass spectrometry( SPME- GC- MS) method,and the volatile compounds were analyzed by the principal component analysis.The results indicated that through the principal component analysis,eight volatile flavor compounds could be selected two main components,the principal components was 97.362%,and they could be classified into three kinds: acid,ester,heterocyclic,alcohol,aldehyde,ether,ketone and hydrocarbon.Freeze- thaw process could not add the varieties of flavour substances from the analysis of specific volatile flavour compounds,and the kinds of flavour compounds in cooked Tan mutton had obviously increased as the thawing temperature decreased,among the increased volatile flavor compounds,there were five kinds of hydrocarbons,three kinds of esters,one kind of acids and two kinds of ketones.