Abstract:Douchi which is combined nutrient value and health-care function is a microbe-fermented soybean food. Flavor, to some extent, determines directly the quality of douchi and consumers’ acceptability. Douchi which is fermented with a pure Bacillus sp. will make a single flavor and have ammoniacal odour at different degrees. Mixed-fermentation with Lactic acid bacteria (LAB) can improved significantly the flavor of douche. The article summarizes the main flavor substances of bacteria-fermented douchi, and the possible forming mechanisms of the flavor substances which produced by LAB were emphatically discussed. The paper will provide theoretical support for further improving the flavor of douchi and reasonably controling the production process.