Abstract: Volatile compounds in samples collected at different stages during the insulation fermentation of sweet flour paste were analyzed by the headspace solid- phase microextraction( HS- SPME) combined with gas chromatography- mass spectrometry(GC- MS). The major volatile flavor compounds during the whole insulation fermentation process included 9 alcohols,20 esters,10 aldehydes,2 phenols,1 ketone,2 furans,2 alkanes and 3other compounds as demonstrated by principal component analysis(PCA) of their relative contents. More volatile compounds were detected as the insulation fermentation proceeded.PCA analysis suggested that the best flavor of sweet flour paste was achieved after 7 weeks( about 49 d) of insulation fermentation.