Influence of Lactic Acid Bacteria on the Flavor of Fermented Soymilk Five Streptococcus thermophilus stored in laboratory with different sensory characteristics of fermented soymilk were studied.The activities of enzymes from lactic acid bacteria such as α-acetolactate decarboxylase(α-ALDC),α-galactosidase,β-galactosidase,and lactate dehydrogenase(LDH),and the characteristics and flavor compounds of fermented soymilk were measured.Their correlation was also discussed.The results showed that the sensory evaluation of fermented soymilk was significant negatively and positively correlated with α-ALDC and α-galactosidase respectively,and was significant positively correlated with flavor compounds of 2,3-butanedione,2-heptanone and 2-nonylketone,was significant negatively correlated with hexanol,2,4-decadienal and 2-pentylfuran.Simultaneously,the acidity of fermented soymilk was significant positively correlated with β-galactosidase and LDH.