Abstract: To optimize the extraction process of luteolin from Botrychium ternatum and to investigate its antioxidant activity. In this study, single factors and orthogonal experiments were used to optimize the extraction process of luteolin from Botrychium ternatum, and the optimal extraction conditions were obtained. The scavenging abilities on free radicals including 2,2-diazo-bis（3-ethyl-benzothiazole-6-sulfonic acid） diamiammonium salt（ABTS+）, 1,1-diphenyl-2-trinitrophenylhydrazine（DPPH）, hydroxyl free radical（·OH） and total reducing power of the extract were determined to investigate the antioxidant activities. The results showed that the optimal extraction conditions were determined as follows: ultrasonic time of 25 min, liquid-solid ratio of 25∶1（mL/g）, ethanol volume fraction of 60%, and ultrasonic temperature of 85 ℃. The extraction amount of luteolin was 4.88 mg/g under these conditions. The results of antioxidant tests showed that the IC₅₀ values of DPPH·, ·OH and ABTS⁺ free radical scavenging rates of the extract were 14.9, 78.6 and 80.2 mg/L, respectively, indicating that the extract could be a potential natural antioxidant. This study provided theoretical basis for the development of the resources of Botrychium ternatum. The optimized extraction process of luteolin from Botrychium ternatum is reasonable and feasible, and the extract has superior antioxidant activity.