Abstract:The relationship between leaf characteristics and environmental factors was determined in Jasminum humile L. grown in the dry valley of the upper Minjiang River. The leaves were elliptic and leaf mesophyll tissue was distinctively differentiated. Leaf area, leaf thickness, leaf dry weight, leaf saturated water content, spongy tissue thickness, main vain thickness and the ratio of main vein thickness：collenchyma thickness （the V:C ratio） increased with increasing elevation. The ratio of palisade:spongy （the P:S ratio） declined as elevation increased. No significant differences were found in the ratio of leaf length: leaf width, epidermal thickness, palisade tissue thickness and leaf mass per area along elevation gradient. There were significant and positive correlations among leaf area, leaf dry weight, saturated water content, total leaf thickness and spongy mesophyll thickness, while all of these parameters were negatively correlated with the P:S ratio. Leaf area, leaf dry weight, spongy mesophyll thickness and the V:C ratio increased mainly with increasing soil water content. However, the P:S ratio decreased with increasing soil water content and annual rainfall. Leaf thickness, leaf saturated water content and vein thickness increased with decreasing temperateness. It is likely that leaf traits in J. humile are affected mainly by soil water content and temperature during the growing period in the habitat.