Abstract: Components of FJAT-0809-GLX fermentation liquid in10 different initial pH values were analyzed by GC-MS. Eleven compounds with the match degree above 90% were identified. The compounds found commonly in these 10 fermentation liquid was Hexahydro-pyrrolo pyrazine-1,4-dione.There were two sorts of functional compounds in the FJAT-0809-GLX fermentation liquids; one is volatile compounds which relate to the special aroma of this fermentation liquid, including 5-methyl-2-Furancarboxaldehyde,Maltol,Benzeneacetaldehyde, n-Hexa-decanoic acid, Oleic Acid, and 2-Hydroxy-3-methyl-2-cyclopenten-1-one. The other sort of functional compound had antiseptic and bacteriostatic effect, including Maltol, 2-Furanmethanol and Hexahydro-pyrrolo pyrazine-1,4-dione and 5-(hydroxymethyl)-2-Furancarboxaldehyde. The fermentation liquid with the initial pH value of 6 to 12 had inhibitory activity against K88.The pH value 7 had the best inhibitory activity; the diameter of inhibition zone was 20.33mm. Different initial pH values led to different terminal pH value, and then affect the generation properties of secondary metabolites of Brevibacillus brevis FJAT-0809-GLX.