Abstract:Global changes impose a profound impact on the xylem formation, which in turn affects the carbon sequestration of forest ecosystems and fundamental services of global ecosystems. The xylem formation dynamic of tree is mainly characterized by the timing of the onset and the end of cambial activity, the length of the growing season, and the growth rate, etc., which are jointly regulated by various factors, such as phytohormone, carbohydrate, nitrogen and meteorological factors. By investigating the formation dynamics of xylem over a fine time scale, the determinants of xylem formation could be revealed, the understanding of physiological mechanism of tree growth would be deepen, and the prediction accuracy of the tree growth response to climate changes would further improve. The recent research progresses in the xylem formation dynamic and its regulation mechanism were reviewed, and the prospects for the future research were provided.