Abstract: Objective]Although leaves of Halostachys caspica degenerate into a scaly shape and don't play a major role in plant photosynthesis,but they are very sensitive to the changes of environment.[Method]As an important organ,the leaf cell structure was observed under different salt concentration stresses by micro-scopes.[Result]With the increase of salt concentration,the leaves of H.caspica were getting thicker progres-sively,cells arrangement from loose to tight,and crystal and storage cells became larger and more.Papillary-like bulge of epidermal cell wall showed a gradual increase in the outward convex shape,which could fully absorb the water.The variation in papillary-like to hair-like bulge of leaf epidermal cell wall indicated that water content in cells was decreased.More crystal in the leaf epidermal and stomata showed that the cuticle of epidermal cells and stomata of H.caspica could secrete salt.[Conclusion]H.caspica is an excessive mixed halophyte plant both aggregating salt and salt secreting.300 mmol/L-500 mmol/L salt concentrations are the best salt concentrations for the growing of H.caspica,and leaf cell structure is normal under those salt concen-trations.