Reaumuria soongorica is a main dominant and constructive species of the desert shrubbery vegetation in arid region. We tried to investigate the variations in foliar characteristics of this desert plant and identify the major factor which influences the variations in the major distribution areas. 21 populations were selected at altitudes 394-1987 m, latitudes 36°10′-44°33′N and longitudes 81°43′-106°37′E. We measured nitrogen, phosphorus, potassium, organic and water contents in leaves of 407 individuals, and soil physicochemical properties including nitrogen, phosphorus, organic, water contents and total dissolved solids. Soil conditions had significant effects on foliar traits. Increased soil water content enhanced leaf nitrogen and leaf water contents in R. soongorica, and decreased leaf potassium content significantly. The soil nitrogen, phosphorus contents and total dissolved solids were positively correlated with leaf phosphorus, but negatively correlated with leaf water content. Leaf nitrogen content decreased and leaf water content increased significantly with increasing soil pH. We concluded that soil water content was the primary factor affecting foliar characteristics and that leaf water content was particularly influenced by environmental factors in different natural populations. Leaf water content in the desert plant R. soongorica respond to soil conditions reinforces that it is a super-xerophil improved water-use efficiency in this adaptive strategy to desert environment.