Objective:To investigate the responses of baicalin through oxidative damage of human periodontal ligament cells（h PDLCs）after exposed to hydrogen perioxide（H

2

O

2

）. Methods:The h PDLCs were cultured from healthy adult premolar teeth. Cell counting kit-8（CCK-8）was used to detect cell proliferation and activities. Appropriate concentration and time of H

2

O

2

was chosen to establish the model. Hoechst33342 fluorescent staining was used to observe the cell nucleus of apoptosis. Fluorescent staining technique was combined with cytometry to investigate the influence of baicalin on the apoptosis and necrosis of H

2

O

2

exposed cells. The leakage rates of LDH and MDA were calculated by spectrometer thus to elucidate the protective effect of baicalin on human periodontal ligament cells.Results:Results of CCK-8 showed that at a concentration of 200 μmol/L

the optical density of H

2

O

2

was different from other groups（F=24.113

P=0.001）. The typical cell nucleus of apoptosis was revealed by fluorescent staining. Flow cytometry showed that 1 to 10μg/m L baicalin can protect h PDLCs exposed to H

2

O

2

. At the concentration of 1 μg/m L

baicalin can decrease the amount of the total cell LDH

&

MDA leakage rates than the model group cells

even than the other concentration groups. Conclusion:H

2

O

2

at the concentration of 200 μmol/L renovate oxidative damage on h PDLCs. Baicalin at a concentration of 1 μg/m L protect h PDLCs of H

2

O

2

damage.