Abstract: 【Objective】To explore the drought resistance of Lespedeza bicolor seedlings under drought stress.【Methods】The growth characteristics,photosynthetic characteristics,and physiological changes of Lespedeza bicolor seedlings under drought stress were studied using 2-year-old seedlings as experimental materials. Four treatments were set up：control（CK,field water capacity 75%-80%）,mild drought（T1,field water capacity 60%-65%）,moderate drought（T2,field water capacity 45%-50%）,and severe drought（T3,field water capacity 30%-35%）.【Results】Lespedeza bicolor newly emerged shoot length,shoot diameter,leaf number,and proline content increased first,then reduced as drought stress increased,peaking in moderate drought. Chlorophyll,malondialdehyde,soluble protein,and catalase（CAT）and superoxide dismutase（SOD）activity all varied dramatically,peaking in mild drought. Peroxidase（POD）activity had decreasing trend. Between T2 and T3,there was no significant difference（P>0.05）. The net photosynthetic rate（P_n）,transpiration rate（T_r）,and stomatal conductance（G_s）of Lespedeza bicolor all reduced linearly as drought stress increased. Intercellular CO₂ concentration（C_i）changed in the opposite direction as P_n under mild drought and followed the same changing pattern as P_n during severe drought.【Conclusion】Lespedeza bicolor seedlings could withstand moderate drought stress. Mild drought is the ideal environment for seedling growth.

Key words: Lespedeza bicolor seedlings, Drought stress, Photosynthetic characteristics, Physiological response