Abstract: Turmeric( Curcuma longa L.) is a plant belonging to the family of Zingiberaceae,it has been commonly used in Chinese traditional medicine and food coloring. In this study,the turmeric essential oil was extracted by steam distillation,and its antioxidant capacity was evaluated based on ABTS radical and hydroxyl free radical( ·OH) scavenging activities,inhibition of lipid peroxidation in linoleie acid. Its cytotoxic effect on Hep G2 cells was evaluated by mitochondrial- respiration- dependent 3-( 4,5- dimethylthiazol- 2- yl)- 2,5- diphenyltetrazolium( MTS) assay,the antioxidant effect in cell levels was investigated by flow cytometry. The results indicated that turmeric essential oil exhibited good scavenging activities against ABTS free radicals,but the scavenging rate was lower than that of V_E.The essential oil could significantly scavenge ·OH radicals,the scavenging rate was similar with that of V_E. And it could inhibit lipid peroxidation in linoleie acid. Within the concentration of 0.02%( v / v),the essential oil had no obvious cytotoxicity on Hep G2 cells,and could scavenge the reactive oxygen in them. It is suggested that turmeric essential oil could be developed as a food addictive of natural antioxidants.