In order to explore the aroma composition and antioxidant activity of Dendrobium bensoniae Rchb.f.flower,the volatile extract of D. bensoniae was obtained by solvent-assisted flavor evaporation (SAFE) and the antioxidant activities of its extracts were evaluated by three kinds of free radical scavenging models in vitro combined with SOD activity repair model in human immortalized cortical cells.The chemical composition of the volatiles was analyzed by GC-MS and the relative percentage of each compound was determined by peak area normalization method.Odor active value of each compound was calculated based on its relative percentage and accordingly odor threshold,which indicated the key aroma compounds in D. bensoniae flower.The research results showed that a total of 51 compounds were identified from the flower volatiles,accounting for 90.0% of the total content.Among them,16 key aroma compounds,6 modified aroma compounds and 3 potential aroma compounds were identified,including benzyl alcohol (45.5%),vanillin (17.0%),hexanal (3.4%) and phenylethyl alcohol (2.7%),which responsible for the aroma characteristics of grass,sweet and floral notes of the flower.The material extracted by high concentration ethanol from D. bensoniae flower showed strong antioxidant activity in hydroxyl free radical scavenging,DPPH free radical scavenging,ABTS free radical scavenging bio-assays and SOD activity repair model in human immortalized cortical cells.The results of the present study provide a scientific basis for the research and development of D. bensoniae flower related products and antioxidant substances.