Abstract: Northeast China located at the intersection of the northern margin of the East Asian Monsoon and the westerlies, is highly sensitive to global climate changes. The lake sediments in this region feature strong continuity and abundant information carriers, making them ideal for reconstructing the evolution of paleo-environments and paleo-ecosystems. This study systematically reviews the climate changes, ecosystem responses, and impacts of human activities recorded by lake sediments in Northeast China since the last glacial maximum (LGM). Research shows that the climate in Northeast China generally showed a pattern of being dry and cold during the LGM and warm and humid during the Holocene. However, since the last deglaciation, spatiotemporal heterogeneity may exist in hydroclimatic variations on a millennial scale, and the quantitative temperature reconstructions also exhibit significant uncertainties and regional differences. Dust in Northeast China is mainly sourced from the deserts in northern China and the arid regions of Mongolia. Its flux and intensity variations are closely related to climate changes and human activities. Vegetation gradually evolved from the frigid grassland during the LGM to the coniferous-broadleaved mixed forest during the Holocene, and the lake ecosystem underwent phased transformations following changes in hydrology and nutrient status. In modern times, human activities have become an important driving factor of environmental change, leading to the accumulation of lake pollutants, an increase in dust input, and regional ecosystem degradation . High-resolution multi-proxy integration, the identification of human-nature coupled processes, and the integration of models and records should be strengthened in future research. These are better for understanding regional environmental evolution mechanisms and improving future prediction.

Key words: Northeast China, lake sediments, Holocene, climate change, ecological response, human activities, last glacial maximum