Sequence analysis of the D1/D2 region of 26S rDNA was used for the identification of 12 yeast strains isolated from 8 kinds of food samples.The 12 yeast strains were identified by sequence homology comparison with known sequences in GenBank as follows: were Saccharomyces cerevisiae(A1,S2,and S3 strain),Torulaspora delbrueckii(N and Y strain),Kluyveromyces marxianus(S6 strain),Pichia cactophila(YOH strain),Clavispora lusitaniae(XZ strain),Pichia membranifaciens(P3 strain),Pichia kudriavzevii(H and S5 strain),and 1 unidentified new species(S4 strain).The free volatile compounds produced by the yeast strains were detected by gas chromatography-tandem mass spectrometer combined with SPME.Most of volatiles detected were Esters,including ethyl acetate,ethyl octanoate,phenethyl acetate,ethyl decanoate.etc.Most of volatiles detected by SPME-GC/MS were similar among all isolated fementation.Contents variation depended on different strains,and strain A1 could produce special volatile compound ethyl caproate and the appropriate proportion of free volatile compounds.The result showed that the kinds and content of free volatile compounds are in significant relation with yeast species and food sources,that maybe caused by the difference in metabolic pathways of volatiles.