OBJECTIVE To Study the antioxidant activity of Herba Lycopi, and screen the main active fractions. METHOD The different polar fractions were isolated from the ethanol extract of Herba Lycopi. The scavenging activity to DPPH and superoxide anions, reducing effect on Fe3+, and inhibiting activity of lipid peroxidation of the fractions were studied in vitro by high-throughput screening technique. RESULT The ethanol extract, ethyl acetate fraction (LLE-A. E, MCCM2921) and n-buthanol fraction (LLE-A. B, MCCM2922) of Herba Lycopi showed the scavenging activity to DPPH and superoxide anions, reducing effect on Fe3+, and inhibiting activity of lipid peroxidation. CONCLUSION The ethanol extract and different polar fractions showed antioxidant capacity in vitro. That may be explain that the effect of activating blood and dissolving stasis and anti-fibrosis of Herba Lycopi in traditional application. The results may be helpful for further development of Herba Lycopi as a low-toxic antioxidant drug.