Objective:To investigate the effect of active part of spatholobus suberectus flavonoid（SSCE） on oxidative stress in human pulmonary adenocarcinoma cell A549.Method:Cells were divided into a high-dose group

a moderate-dose

a low-dose group and a normal control group.Cell A549 were interfered with different dosages of SSCE active part for 24 h（normal group with DMEM） level of malonic dialde hyde（MDA） and glutathione（GSH）;reactive oxygen speiesROS was detected using fluorescence microplate reader and confocal fluorescence microscope

and using DCFH-DA as fluorescent probe;Antioxidant was added

CCK-8 was employed to detect cell proliferation of A549 and ROS was detected by fluorescence microplate reader.Result:After the addition of SSCE

MDA content in each group increased（P<0.01） and GSH content in high density group decreased（P<0.01）;Cell ROS content in high and middle density groups increased（P<0.01）;Each group showed green fluorescence under confocal microscope

in which the high and middle density group showed higher;Addition of antioxidant made decrease of cell inhibition（P<0.05） and ROS content（P<0.01）.Conclusion:SSCE can change the level of A549 MDA

GSH and ROS

and its mechanism of antitumor might be inducing oxidative stress reaction of tumor cells.