Eupatoriurn odoratum aerial parts were extracted with ethanol using ultrasonic-assisted extraction (UAE). Total phenolic content (TPC) and total flavonoid content (TFC) were used to quantify antioxidant compounds with the values of 2.772±0.3 mg GAE (Gallic acid equivalents)/g DW and 7.085±0.2 mg of RT (Rutin)/ g DW. The activities of scavenging 2,2′-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6 -sulphonicacid) (ABTS) radicals, hydroxyl radicals, ferric ion reducing power and ferrous ion-chelating activity were analyzed, with IC50 values of 3.00, 1.08, 1.18, 0.14 and 3.16 mg/ml, respectively. The study offers theoretic basis for pharmaceutical utilization of the medicinal plant E. odoratum.