Abstract: Objective:To study the effect of Pleurotus nebrodensis polysaccharide on the life-span of Drosophila melanogaster. Methods:In this study,the effects of polysaccharides from P. nebrodensis on average body weight,reverse gravity crawling ability,longevity and anti-oxidation activity of Drosophila melanogaster were studied.Results:Compare with the control,feeding with 0.50% of P. nebrodensis polysaccharide significantly increased the reverse gravity crawling ability(p<0.01)and the average body(p<0.05)weight of D. melanogaster. The average life-span of D. melanogaster(females increased by 22.77%,males increased by 21.01%,p<0.01),the half-death phase(females increased by 23.08% and males increased by 27.86%,p<0.01),and the longest life-span(females increased by 18.24% and males increased by 20.05%,p<0.01). The test of antioxidant activities of D. melanogaster which was fed in 30 days showed that the activities of superoxide dismutase(SOD)and catalase(CAT)were increased significantly and the MDA content decreased significantly in 0.50% dose group(p<0.05). Conclusion:The PNPs could increase a series of antioxidant enzyme activity,reduce lipid peroxidation,to extend D. melanogaster longevity pathways.