The α-glucosidase inhibitory activity of whey from fermented skim milk by 11 strains with milk curding ability which were selected from 14 Lactobacillus casei strains,assayed in vitro enrolling maltase(EC 3.2.1.20) as the targeting enzyme.It was showed that the α-glucosidase inhibitory activity of Lb.casei was strain specific,with a significant increase in inhibitory intensity with the fermentation elongated for those strains demonstrated α-glucosidase inhibitory activity.Among the tested Lb.casei strains,Lb.casei LC2W(CGMCC0828) demonstrated the strongest α-glucosidase inhibitory activity,with an inhibitory percentage of 37.36% for whey derived of 10%(w/w)skim milk fermented at 37℃ for 96 hours.These results suggested Lb.casei LC2W has the potentials of antihyperglycemia as well as anti-diabetes.