Abstract: The antioxidant capacities of bitter almond oil were evaluated in vitro and in vivo. In this study, vitamin C was used as control for antioxidant tests in vitro, and the scavenging abilities of bitter almond oil on DPPH radical, superoxide anion radical（O₂^-·）, hydroxyl radical（·OH） and the reducing ability of Fe³⁺were determined.Subsequently, Vitamin E was used as the control group for in vivo antioxidant evaluation. Five groups of mice were given with different concentrations of bitter almond oil, respectively. After 4 weeks of continuous gavage,50% ethanol solution was perfused to cause oxidative damage. After 6 h, the superoxide dismutase（SOD） activity and malondialdehyde（MDA） content in sera were measured. The antioxidant tests in vitro showed that bitter almond oil presented certain scavenging abilities on DPPH·, O₂^-·, ·OH, and the half scavenging rates dosages(IC₅₀) were 0.215 mg/mL, 0.378 mg/mL, 0.679 mg/mL, respectively, which also had a certain reduction ability on Fe³⁺. The in vivo antioxidant test showed that bitter almond oil could increase SOD activity and reduce MDA content in mice sera, and the dosage of 0.15 mL/g m_b had the best effects. The results of this study could provide a theoretical foundation for the antioxidant development of bitter almond oil.