In order to explore the adaptation mechanism of Cyclobanopsis glauca seedlings to "drought-rehydration" environment in karst area, using the current growth seedlings of C. glauca as materials, the pot water control experiment was carried out. The effects of four soil drought stress treatments (control (–0.1 MPa), mild drought (－0.5 MPa)), moderate drought (–0.9 MPa) and severe drought (–1.5 MPa)) and rehydration treatments on water status, photosynthesis, chlorophyll fluorescence and anatomical structure parameters of leaves were studied. Results show that: (1) With the increase of drought stress intensity, leaf relative water content, water potential, net photosynthetic rate (Pn), transpiration rate (Tr), stomatal conductance (Gs) and intercellular CO2 concentration (Ci) were significantly decreased, and stomatal limitation (Ls) increased significantly. Photosynthetic parameters under mild stress and instantaneous water use efficiency (WUE) under mild and moderate drought stress were not significantly affected. After rehydration, leaf water parameters, Pn, Tr, Gs, Ci and WUE under each drought stress treatment were were higher than those before rehydration, while Ls was lower than those before rehydration.. The leaf water conditions and photosynthetic parameters under mild drought stress were significantly better than those of the control after mild stress rehydration, only Ls under moderate drought stress did not recover to the level of the control after rehydration, and neither leaf water content nor photosynthetic parameters under severe drought stress recovered to the level of the control after rehydration. (2) With the increase of drought stress intensity, the initial fluorescence (Fo) of leaves increased significantly, while the maximum fluorescence (Fm), maximum photochemical quantum yield (Fv/Fm) and potential photochemical efficiency (Fv/Fo) of leaves decreased significantly. There were significant differences in these parameters between mild drought stress and control. After rehydration, Fm, Fv/Fm and Fv/Fo under each drought stress were higher than those before rehydration, whereas Fo was slightly lower than that before rehydration. All the chlorophyll fluorescence parameters after rehydration under mild stress recovered to or better than those of the control. Fo under moderate and severe drought stress did not return to the control level after rehydration, and Fv/Fm under severe stress was only 0.75 after rehydration. (3) With the increase of drought stress intensity, leaf thickness, upper and lower epidermis thickness, stomatal density, and main vein conduit diameter increased significantly, length and width of stomatal apparatus, stomatal opening area and sponge tissue thickness decreased significantly, while palisade tissue thickness, ratio of palisade tissue thickness to spongy tissue thickness and main vein thickness were moderate > mild > control > severe drought stress. After rehydration, only the stomatal opening area and the thickness of main leaf veins of each drought stress increased significantly compared with that before rehydration. After rehydration, the leaf structural parameters under mild drought stress were restored to or better than those in the control. The stomatal opening area after rehydration in moderate drought stress was still significantly lower than that in the control group. After rehydration, the stomatal opening area in severe drought stress failed to recover, and the thickness of main veins in severe drought stress was lower than that in the control. Therefore, the seedlings of C. glauca have drought tolerance and post-drought recovery ability, which is suitable for ecological restoration tree in karst area, but the seedlings should be protected from moderate drought stress (-0.9mpa) in the nurturing stage, so as to facilitate their post-drought recovery.