Abstract: Objective: To investigate antioxidant activities in vitro of different polarity fractions of ethanolextract and GC-MS analysis from Volvariella volvacea fruiting bodies.Methods: Volvariella volvacea was extracted with volume fraction of 95% ethanol reflux extraction,and decompressed concentrating to obtain ethanol extract,then four different polarity parts of Volvariella volvacea extracts were prepared by the addition of petroleum ether,chloroform,ethylacetate and butanol layer. The antioxidant activity in vitro of different polar parts of Volvariella volvacea extracts were investigated by the total antioxidant capacity,DPPH free radical scavenging activity,ferric reducing ability and ABTS radical scavenging activity,and 2,6-ditert butylated hydroxytoluene( BHT) was the control.Results: 49 compounds were analyzed from the Volvariella volvacea fruiting bodies by GC-MS analysis,which mainly included alkanes,fatty acids,aldehydes,esters,alcohols,ketones,and the content was respectively22.54%,19.94%,15.38%,13.08%,7.33%.Through the determination of four in vitro antioxidant capacity,straw mushroom ethanolic extracts of different polar parts all showed antioxidant activity,which layer of ethyl acetate and butanol layer showed good antioxidant activity and the chloroform layer of antioxidant activity was the lowest.Within the set concentration range,the total antioxidant capacity,DPPH free radical scavenging rate and iron ion reduction ability of the ethyl acetate layer were significantly higher than those of other layers( p < 0.05).In the ABTS free radical scavenging system,the ABTS radical scavenging rate of the normal butanol layer was higher than that of the ethyl acetate layer,but the difference was not significant( p > 0.05). Conclusions: Through the analysis ofGC-MS and test of antioxidant activity of the fruiting body,ethy lacetate fraction and normal butyl alcohol fraction,which were a kind of good source for natural antioxidants,showed relatively strong antioxidant activities,and were worth separating and purifying further.