Water stress affects the photosynthetic pigments in leaves of Cynanchum komarovii. The study found that chlorophyll and carotenoid levels in the leaves did not decrease much initially, but decreased significantly over time. The chlorophyll fluorescence parameters showed little change, with Fo decreasing and Fm, Fv, and Fv/Fm increasing under water stress. This suggests that prolonged water stress can impact photosynthesis in Cynanchum komarovii, but the plant shows high adaptability to such conditions.