Abstract: To study changes in Yibin sprouts flavor substances in the case of the fermentation process,using HS-GC-MS method for sample Yibin sprouts different periods of fermentation process analysis to the data sample analysis method to study the main characteristics of flavor with principal component analysis.The results showed that:different fermentation periods were detected in 78 kinds of flavoring substances,thereinto olefin(21 kinds),alcohols(23 kinds),esters(12 kinds),aldehydes(4 kinds),ketones(7 kinds),ethers(3 kinds)and benzene ring( 6 kinds) and the like, a total of six main components were extracted and a greater impact on the Yibin sprouts flavor substances 12 kinds using principal component analysis. Through the study of this paper could grasp the change of flavor in the fermentation process of bean sprouts,bean sprouts,provides the theory basis for the improvement of the flavor and new product development.