Abstract: Objective:To study protective effect of argyi wormwood flavonoids on WBC and major organs of X-ray irradiated mice.Methods:Mice were randomly divided into 5 groups, normal control group, radiation control group, low-dose group (30mg/kg) , medium-dose group (60mg/kg) , high-dose group (90mg/kg) .20 mice in each group, every mice were gavaged twice a day (morning and evening) , 2mL each time.The mice were irradiated 210s every time for 15 days by 1.0Gy X-ray.The body weight, WBC were determined and the activities of SOD, MDA in major organs were assayed respectively.Results:The detection of indicators of medium-dose group were little difference copared with normal control group, but significant difference copared with radiation control group.Conclusion:It was showed that a certain dose of wormwood flavonoids could inhibit damage and toxic to WBC and major organ by X-ray irradiated.