Abstract: The changes of chlorophyll, relative water content, membrane permeability and maloondiadchyde(MDA) were analyzed in spinachleaves during water loss and wilting. The results indicated that the chlorophyll centent decreased while permeability and MDA centent increased as the relative water centent in wilting and senescence leaves decreased. The permeability and MDA centent increased significantly with the increase of wilting of the leaves. It seemed that there was a close relationship between water loss and wilting and the damage of membrane system.