Abstract: In order to understand the relationship between the anatomical structure and the salt-tolerant characteristics of strong salt-tolerance plants, the stomatal density, stomatal aperture, epidermal hair, ergastic substance and water potential of the leaves of wild Nitraria Tangutorum B. and Suaeda glauca B. were measured by quick section and microscopic examination. The results show that Nitraria was 50% more on leaf water potential, 1.7 times more on stomatal aperture, 25 times more on epidermal hair, but 43% less on stomatal density than Suaeda. It was inferred that the salt tolerance of Suaeda should be relate to the decrease of water potential and the stomatal aperture in soft, succulent and rounded leaves, and Nitraria should be connected with the lower stomatal density and a lot of epidermal hair. Furthermore, a mass of brown ergastic substance in cells of Nitraria should play an important role on its water holding, antioxidation and salt tolerance.

Key words: stomatal density, stomatal aperture, epidermal hair, ergastic substance, salt-tolerant plant