Abstract: In onder to find new and active α-glucosidase inhibitors,the medium composition of a sponge-associatedbacterium Bacillus fimus,which had been found possessing α-glucosidase inhibition(α-GI)activity in the previ-ous studies,was optimized through the orthogonal test.The active components in crude extracts of this strain werealso isolated and analyzed.For an effective αglucosidase inhibition,rapid cell growth(in terms of cell wet weight)and high crude extract production of the metabolites,an orthogonal test was conducted and it indicates that the com-bination of peptone 3g/dm³,yeast extract 3g/dm³,NaCl 19.5g/dm³and pH=7.5 is the optimal conditionsbased on the MB medium.The strain was fermented in large scale under the optimized conditions and the metabo lites cude extract was extracted.After twice separation guided by αGI activities on silicagel column,a sub frac-tion with high activity of 82.4%against αglucosidase was then obtained.The GC-MS analysis indicates that cyclicdipeptides and piperidones contributed major components in this active sub-fraction.Present study provided a newand applicable resource for the promising αglucosidase inhibitors.