Few studies have examined leaf-trait relationships in the distribution of individual species along an environmental gradient. Here we address the issue by testing for the leaf-trait relationships of Quercus liaotungensis, a dominant deciduous woody species in northern China, along an altitudinal gradient in Dongling Mountain, Beijing. These leaf traits included specific leaf area (SLA), leaf dry matter content (LDMC), and leaf nitrogen, phosphorus, and potassium concentration on mass basis (N mass , P mass and K mass , respectively). Along the altitudinal gradient, negative relationships between SLA and LDMC and N mass were found, and N mass , P mass and K mass correlated with each other positively. Relationship between N mass and P mass was stronger than the ones between N mass and K mass , and between P mass and K mass . The weak and negative relationship between SLA and N mass might result from trade-offs that limit photosynthesis and water use efficiency along the altitudinal gradient, suggesting many environmental factors of local site being the collective forcing of drivers. Out of our expectations, N mass and P mass related very weakly to soil N and P, and no significant relationship between K mass and soil K was found along elevation. These relationships could be used to predict the productivity of the population with changing environment in this region.