The 5th Academic Symposium on Dendrochronology of China focusing on “Tree Rings, Forest Ecology -Climate and Environmental Changes” was held in Harbin, China, on January 18-21st, 2018. It was organized by Northeast Forestry University, Institute of Earth Environment of Chinese Academy of Sciences (CAS), Institute of Botany of CAS, Shenyang Agricultural University and Institute of Applied Ecology of CAS. The conference aimed to strengthen communication and cooperation among tree ring researchers in China and neighbouring countries, and to better understand the changing global environment and human cultures via dendrochronology science. More than 280 participants discussed the present and future of dendrochronology with topics ranging from dendroclimatology, forest ecology and glaciology, to wood anatomy, dendroarchaeology and tree physiology. In total, more than 90 oral presentations and 17 posters were presented, covering many different aspects of tree ring research. The conference also provided a one-day excursion to the upper tree line to Snow Kingdom-Mudanjiang, Heilongjiang, China.