Abstract: Plant leaf morphological traits adapt to the environment through long-term evolution and are closely related to the basic function of plants. In this study,we examined the responses of leaf morphological traits of broadleaved woody plants to the climatic gradient of Changbai Mountain in northeastern China. We measured plant leaf morphological traits from 13 altitudes in Changbai Mountain, including leaf length, leaf width, leaf perimeter, leaf area, the ratio of leaf length to width (LW) and the ratio of leaf perimeter to area (PA). Correlation analysis and standardized major axis were used to investigate the relationships between plant leaf morphological traits and climate factors, as well as correlations among leaf morphological traits, and general linear model and variation partition were used to partition leaf trait variation and to analyse the leaf traits in relation to environmental factors and species identities. Leaf length, width, perimeter and leaf area decreased significantly with increased altitudinal gradient and decreased annual temperature, while the perimeter/area and length/width ratios increased, which helps increase the leaf boundary layer resistance and decrease heat dissipation from leaves. Variations in leaf morphological traits in this study are largely explained by species identity, with its independent explanatory power between 47.08% and 76.07%. Environmental factors also have a significant impact on leaf morphological traits, but by itself explained only 1.22 % -3.82% of variation.