A number of studies have shown that the global ecological environment has experienced tremendous changes with the global warming.However,in relatively warming climatic conditions,it is still poorly understood that the vegetation ecological responses to major/abrupt cooling events.The Northern China can be roughly divided into three regions based on vegetation and climate,including the climatically westerlies dominated arid and semi-arid areas in Central Asia,the marginal areas of the Asian summer monsoon with highly variable climate and vegetation,and the vast monsoon area in Northern China with relatively high precipitation and better vegetation.We combined published pollen data and climate change records spanning the Holocene in Northern China and nearby areas to explore the major vegetation ecological responses to abrupt climate change.Based on the Holocene high-resolution paleoclimate records and pollen records published in recent years,the cooling events around 7 ka (1 ka = 1000 cal.a B.P.) in the Middle Holocene and their impacts on vegetation ecology were reviewed.This review shows that the cooling events at around 7 ka are recorded in a wide area of the Northern Hemisphere,accompanied by climate drought in the edge of the Asian summer monsoon area,while,in the arid area dominated by the westerlies,the climate was generally humid.In different areas of the Northern China,the vegetation feedbacks were quite different.The major plant species changed in the marginal areas of the summer monsoon system under drier climate,which is shown as the decrease of broad-leaved tree species,increase of coniferous tree species,and/or the decrease of vegetation coverage.In the high mountains in Northwestern China,the vegetation feedback was shown as the decrease of tree-line or the change of tree species.While,in the lowland areas surrounding the mountains in Northwestern China,the forest composition increased in the steppe-forest vegetation areas,and vegetation coverage increased in the desert-steppe area with more steppe species.Low temperature directly modified forest compositions and tree-line in the relatively wet high mountains,while,it affected vegetation coverage and composition by increasing humidity/precipitation in arid and semi-arid areas via depressing evaporation.Due to both the uncertainties of chronological data of different studies and the sensitivity of different vegetation types,the timings of vegetation transformations were not consistent.The driving forces of the 7 ka cooling event in the Middle Holocene needs to be further studied,which might be related to the strongest eruptions of large volcanoes,solar activity variabilities.The continuous decrease of summer solar insolation in the Northern Hemisphere and inner feedbacks of the earth system also contributed to this cold period.