Abstract: In order to study the variation of volatile compounds in surimi fermented by lactic acid bacteria, the technology of extraction by simultaneous distillation extraction(SDE) and detection by gas chromatograph-mass spectrometry(GC-MS) of volatile flavor compounds from fermented surimi used as the research object was established. The two methods of natural fermentation and fermentation of surimi with Lactobacillus reuteri were compared, and the change of flavor substances in the process of fermented surimi was analyzed. The results showed that 37 kinds of volatile substances were detected in surimi fermented by Lactobacillus method, and the substances with obvious flavor characteristics were acetic acid, n-hexanal, 1-octene-3-ol, ethyl acetate, etc. And 25 kinds of volatile substances were detected in surimi fermented naturally, among which acetic acid, n-hexanal and 1-octene-3-ol were the main substances. The content of esters, acids, alkanes and alcohols in surimi fermented by Lactobacillus reuteri was higher than that in naturally fermented surimi, which accounted for 1.20%, 2.72%, 1.56% and 11.35% in naturally fermented surimi, while 21.83%, 14.86%, 14.98% and 16.37% in the fermented surimi by Lactobacillus reuteri, respectively. Lactic acid bacteria could improve the sensory quality and flavor of fermented surimi.