Abstract: In order to study the effects of soil water on the epicuticular wax and the growth of shade plant leaves，the blue leaf variety of Hosta‘Halcyon’was grown in pots with 4 kinds of soil water treatments，which were normal water supply，light water stress treatment，medium water stress treatment and severe water stress treatment. The changes of epicuticular wax and physiological characteristics of Hosta‘Halcyon’leaves were studied under different water stress，and the relationships between them were analyzed. The results showed that the epicuticular wax increased with the increase of drought，and the photosynthetic rate，transpiration rate and stomatal conductance of the medium stress treatment were at low level within a certain drought range，which indicated that the Hosta‘Halcyon’improved water use efficiency and enhanced drought resistance by reducing stomatal opening，transpiration rate and leaf water loss under water stress. With the further intensity of water stress，photosynthesis rate，water use efficiency and leaf chlorophyll content decreased significantly，indicating that chlorophyll synthesis was inhibited，and the increase of leaf epicuticular wax decreased leaf surface permeability，thus reducing water dispersion loss in order to reduce the adverse effects of drought on plant growth. In addition，the study showed that the wax directly affected the color of the leaves. The medium stress group had the highest wax content and higher chlorophyll content，so the blue-green leaf was significantly deeper than the severe stress group，and the ornamental value was higher.

Key words: Hosta plantaginea, water stress, leaf, wax, physiological characteristics