Abstract:The formation process of the Quaternary glacial and interglacial cycles, and the response and evolution process of the terrestrial vegetation system are the key issues in the geological period global change research. This paper reconstructs the regional vegetation evolution process since the past 3 Ma by using 121 high-quality pollen data from borehole of LN1 in North China. The study results indicate that the regional vegetation has experienced four major development processes. The climate is relatively warm and humid during the 3-2Ma and the vegetation is deciduous broad-leaved forest, mainly composed of pine, birch, alfalfa, walnut, and alfalfa. The vegetation changes sharply that the proportion of coniferous forest expand of and the broad-leaved forest decrease in the area around 2 Ma. The vegetation changed to coniferous and broad-leaved mixed forest dominated by pine, spruce and birch during 2-1.2 Ma. During the mid-Pleistocene global climate transition period, the regional vegetation changed rapidly, transforming into a shrub land of sap trees at about 1.2-0.7 Ma. After 0.7 Ma, the regional climate was further dry and the regional environment changed to typical grassland vegetation landscape around 0.7Ma. The vegetation changes in the region reflect the trend of aridification and coldness in the North China Plain since the 3Ma and the 2.0 Ma, 1.2Ma, and 0.7Ma climate events are the most prominent. These results reflect that the vegetation evolution process and the gradual decrease of monsoon coincide with the rapid expansion of the Arctic ice sheet since nearly 3 Ma in North China.