Abstract: Objective: To explore the effect of purple yam extract( PYE) on antioxidant function and lifespan in Drosophila melanogaster.Methods: 2 day-old female Drosophila melanogaster were divided into four groups randomly,and supplemented with different doses( 0,0.5,2.0,4.0 mg/mL) of PYE. The life span,activities of antioxidant enzymes and their encoding genes expressions were detected.Acute experiment were performed to investigate the effects of PYE on oxidative stress injury.Results:Compared with the control group,PYE at 2.0 and 4.0 mg/mL could significantly prolong the lifespan of Drosophila melanogaster,and increase the activities of SOD and CAT and decrease MDA level(p<0.05).The mRNA expressions of SOD and CAT with PYE at 2.0 and 4.0 mg/mL were up-regulated significantly( p<0.05),while the Methuselah( MTH) mRNA level was significantly down-regulated(p<0.05). The lifespan of Drosophila melanogaster treated with PYE was extended significantly in the acute tests. Conclusion: PYE has significant antioxidant capacity in vivo and can prolong the lifespan of Drosophila melanogaster by up-regulating the expression of antioxidant genes.