Dr. Sun's main research interests are tree rings and global change. Based on tree-ring width and stable isotopes, he studies the climate change and driving mechanism, hydrological and ecological evolution process and the impact of human activities over the past millennium. He has presided over the youth project of the National Natural Science Foundation of China, the "Western Young Scholars" project of the Chinese Academy of Sciences and the youth project of the Natural Science Basic Research Plan in Shaanxi Provinceof China. At present, more than 60 papers have been published, including 10 first author papers in Climate Dynamics, Ecological Indicators, Environmental Research Letters, International Journal of Climatology, Journal of Geophysical Research-Atmospheres, Science of The Total Environment and other journals.