Leaf is an important organ for plants to obtain resources. Studying the relationships between its functional traits and environmental factors helps to better understand the ecological adaptability of plants to environmental changes. In this study, with the aim of determining the ecological adaptations of desert plants and revealing the environmental factors that influencing the functional traits of them, we investigated a typical desert plant, Tamarix ramosissima, in different habitats (oasis, transition zone and desert) at the northern edge of the Tarim Basin, analyzed the differences in its leaf structure and physiological traits, and established the correlation between them with soil physicochemical factors. The results showed that: (1) the functional traits of Tamarix ramosissima leaves exhibited different degrees of variation, with the greatest variation in leaf area (40%) and the least variation in specific leaf area and soluble protein content (both 15%). (2) The structural traits including leaf thickness and leaf area, as well as physiological traits including leaf soluble protein, proline, and starch contents of Tamarix ramosissima were significantly different among the three habitats (P<0.05), with soluble protein and proline contents reaching the highest levels in desert habitats. (3) There were significant correlations between several functional traits of Tamarix ramosissima leaves. Leaf thickness and starch content were significantly negatively correlated with leaf tissue density (P<0.05), while the correlations between leaf thickness and starch content, soluble sugar content and non-structural carbohydrate content were significantly positive (P<0.01). (4) The RDA analysis revealed that soil environmental factors including soil available phosphorus content, soil water content, pH and bulk density had the greatest influence, and could explain the leaf functional trait variations of Tamarix ramosissima better. This study indicates that Tamarix ramosissima adapts to extreme arid environment by developing ecological responses that varying in leaf functional traits and forming synergistic trade-offs between them. Soil available phosphorus content and soil water content are the most critical soil environmental factors affecting leaf functional traits of Tamarix ramosissima. The findings of this study provide a theoretical basis for the scientific management, conservation, and restoration of desert vegetation in extreme arid region.