Abstract: Leaf hydraulic traits represent the survival strategies of plant in leaf water transport when adapting to external environment. They constraint the whole plant’s water transport and affect its gas exchange and its response to drought. Therefore, studies on leaf hydraulic traits have been the research focus of plantwater relationship. In this paper, the basic indices of leaf hydraulic traits, i.e. wholeleaf hydraulic conductance (K_leaf), leaf xylem hydraulic conductance (K_xylem), and leaf out the xylem hydraulic conductance (K_out-xylem), and the five measuring methods of leaf hydraulic conductance are summarized. Meanwhile, the research progresses are introduced, including the effects of leaf venation traits as well as the environmental factors on leaf hydraulic traits, the tradeoff relations between leaf hydraulic traits and leaf functional traits (e.g. stomatal conductance, leaf water potential, leaf maximum photosynthetic rate), and the relations between leaf hydraulic traits and drought resistance of plants. Two suggestions on further study of leaf hydraulic traits are proposed: 1) combining the leaf hydraulic traits with gas exchange and anatomical structures of leaves, which is help for building a carbonwater coupling model on leaf scale, to further reveal the ecological strategies of leaves in response to the external environmental change and the plant watercarbon investment mechanism; 2) conducting the research on interactions between plant water transport systems (root-stem-leaf) in order to choose species with a safe and efficient water transport system.

Key words: nutrient, non-structural carbohydrate, Quercus variabilis, provenance, thermal tolerance