The effective exploitation of natural products is of great significance. Herein the essential oil from Herba Artimisiae Sieversianae in growth period and flower/ fruit bearing period was extracted by ethanol extraction method. The optimal extraction condition was determined by orthogonal experiment, including extracting 3 times, soaking for 90 min, and the ratios of liquid to solid for Herba Artimisiae Sieversianae in growth period and flower/ fruit bearing period were 10 mL : 1 g and 8 mL : 1 g, respectively. The main components of the products were confirmed by FT-IR and GC-MS, which were cineole, camphor, d-borneol, caryophyllene, cadina-1, 4-diene, calamenene, ethyl palmitate, etc. in herba artimisiae sieversianae in growth period, and camphor, caryophyllene, borneol, neryl formate, etc. in Herba Artimisiae Sieversianae in flower/ fruit bearing period. The radical scavenging activity of the products was determined. The results showed that the IC50 values of the essential oil from Herba Artimisiae Sieversianae in growth period and flower/fruit bearing period for 0. 05 mmol/ L DPPH solution were 0. 40 mg / mL and 1. 66 mg / mL, respectively. The essential oil extracted by ethanol from Herba Artimisiae Sieversianae was confirmed to possess good antioxidant activity.