Abstract: 【Objective】 To discuss(Populus euphratica) the adaptation characteristics of the saline environment and reveal the physiological mechanism of salt tolerance. 【Methods】 P. euphratica leaves in different saline habitats were used as experimental test materials, the ions were determined by boiling water extraction and boiling method, and the anatomical structure of the leaves was observed under light microscope by paraffin sectioning method, and the content of each ion of the leaves and the comparative anatomical structure characteristics of the leaves were studied. 【Results】 (1) In the low-salt environment, the fence tissue in the leaf of P. euphraticawas larger, the leaf thickness, sponge tissue and midvein vascular bundle area were the largest, and the sponge tissue thickness was significantly different compared with other environments. In the medium salt environment, the thickness of the upper and lower epidermis, the area of fence tissue and mucus cells were greater than those of other environments. In a high-salt environment, P. euphratica leaves increased the thickness of epidermis, sponge tissue and leaf thickness. (2) From low salt environment to high salt environment, the contents of Na⁺, Mg²⁺, Ca²⁺, \mathrmHCO_3 ^- and Cl^- in poplar leaves decreased, and the K⁺ content in leaves increased, thus the ion balance in leaves being maintained. (3) Fence tissue, mucus cell area, fence tissue/sponge tissue, and leaf compactness were significantly or very positively correlated with \mathrmHCO_3 ^- and Na⁺, and significantly or very negatively correlated with K⁺;K⁺ in leaves was susceptible to environmental influences, which was significantly correlated with soil pH, total salt and conductivity. The epidermal thickness, mucus cell volume, and grid-to-sea ratio on the leaves were strongly correlated with soil salinity and water content, indicating that when stressed by salinity, they would resist the stress environment by changing their own structure. 【Conclusion】 Under different saline environmental conditions, the leaves of P. euphratica chinensis are mainly regulated and stored in the leaves by salt separators and act on all parts of the leaves, so as to ensure the normal physiological metabolism of the tree body and form different leaf anatomical characteristics to adapt to the environment.