A 1.8 m long core was retreated from Baijianghe mire in the west flank of Changbai Mountains of China in 2016. The peat sequence was dated by AMS 14C and 210Pb/137Cs methods, showing a 1600-y depositional history. Based on the measured porosity, dry bulk density (DBD), TOC%, absorbance and plant macrofossil, we discuss the mire development and environmental change during the last 1600 years. The basin of Baijianghe Mire was a water-logged bottomland between 330 and 660 CE. A strong drought occurred during 530–600 CE caused lowering of water table which provided hydrological condition to form a peatland. Wet climate during 660–800 CE led to enhanced primary productivity and accumulation of plant remains, resulting rapidly development of the mire. Warm but fluctuating wetness conditions during the Medieval Warm Period (MWP, 900–1150 CE) in the study area kept moderate development of the mire. Baijianghe Mire had the fastest development during 1200–1370 CE under relatively wetter and probably warm conditions. Low carbon accumulation of the mire appeared during the Little Ice Age (LIA, 1500–1850 CE) under cold and dry climates. From 1850 CE to 1945 CE, the climate turned to warm and wet. However, the peatland had experienced strong influence by human activity since 1945 CE. The peatland has gradually recovered from artificial drain since 1990s.
