Abstract: Orange oil, tangerine oil and limonene were used as target samples to study their scavenging capacities on ABTS⁺·, DPPH· and O₂^-· and total antioxidant capacity(FRAP value), as well as their antioxidant abilities in vivo and inhibitory abilities to Staphylococcus aureus, Escherichia coli, Bacillus subtilis and Pseudomonas aeruginosa. The results showed that tangerine oil had the best scavenging capacity on ABTS⁺· and DPPH·, their IC₂₅ values were 1.481 and 24.824 g/L, respectively; limonene had the best scavenging effect on O₂^-·, and the scavenging rate was 32.86% at 0.8 g/L. The ferric ion reducing antioxidant power(FRAP) values of limonene, orange oil and tangerine oil were close to each other and weaker than those of BHA. At the mass concentration of 100 mg/L, the catalase(CAT) activities in Caenorhabditis elegans treated with tangerine oil and limonene were about 46 U/mg, which was 1.63 times of that in the untreated control group. Orange oil, tangerine oil and limonene had a relatively good inhibitory effect on S. aureus and E. coli. The inhibitory effect of tangerine oil on S. aureus was close to limonene, and the diameter of inhibition zone was about 11 mm. Orange oil, tangerine oil and limonene had an excellent antioxidant activity in vitro and in vivo, and they were moderately sensitive to S. aureus.