Taking Chorispora bungeana plantlets in vitro as material,we carried out the current study to investigate the effect of drought stress on a Qinhai-Tibet Plateau plant C.bungeana with solid-liquid culture medium.There were four drought levels being Set:the control (without adding PEG-6000,CK),mild drought stress (5% PEG-6000),moderate drought stress (20% PEG-6000),and severe drought stress (40% PEG-6000).The physiological characteristics of C.bungeana seedings in vitro,laying a foundation for adaptation mechanism of C.bungeana in drought environment were investigated.The results showed that:(1)With drought stress became more and more serious,the activity of antioxidant enzyme SOD and soluble sugar content were significantly increased.The SOD peak appeared earlier than that of POD,CAT,and APX.The activities of POD,APX,CAT and MDA content increased at first,and then decreased,which illustrated that all the four enzymes show different responses to drought stress and reactive oxygen species.(2)Hydrogen peroxide(H₂O₂) content and superoxide dismutase(O^-·₂) composition rate in the leaves quantitatively increased with the increase of drought stress over the time course;C.bungeana leaf relative conductivity initially increased,then decreased and increased at last.(3)Correlation analysis showed that,MDA content and the relative electric conductivity,soluble sugar content,SOD,APX activities,O^-·₂ and H₂O₂ contents presented a significantly positive correlation;soluble sugar content and SOD,POD activities,O^-·₂ and H₂O₂ contents presented a significantly positive correlation;the relative electric conductivity and protective enzymes,O^-·₂ and H₂O₂ contents presented significantly positive correlation.The results demonstrated that C.bungeana has a strong drought tolerance,and the membrane lipid peroxidation,osmotic regulator ,antioxidant enzyme system and oxygen reactive participated in the formation of comprehensive drought stress resistance of C.bungeana.And the above physiological indexes have correlations.It partly revealed the physiological mechanism of C.bungeana responding to drought environment.