Objective The Tianshan Mountains in Xinjiang are located in the inner part of the Asia-Europe continent in the transition zone between the westerly and monsoon circulations. They are sensitive to climate change. Researchers remain divided on the Holocene environmental evolution in the region， and supplementing more high-resolution climatic records in the sensitive areas is the basis for clarifying this issue. Methods Samples were taken from the Middle Tianshan Intermountain Basin， and we reconstructed the vegetation and climate change processes in the study area since the Middle and Late Holocene based on the AMS¹⁴C dating results and using sporadic pollen as a paleoclimate proxy. Results From 6 369-3 601 cal a B.P.： The period of Artemisia and Chenopodium was characterized by high content， positive pollen principal component analysis （PCA） 1 scores， and wet-dry fluctuations in the climate， with dryness as the dominant factor and abrupt climate change. From 3 601-2 512 cal a B.P： The period of spruce Picea content was characterized by elevated content， positive pollen PCA 2 scores， and a cold-wet climate. From 2 512-1 016 cal a B.P： The period of Betula was characterized by increased content， positive pollen PCA 1 transition scores， and a warm dry climate. Conclusions The three pollen zones indicate that the Middle and Late Holocene climate in the Zhongtianshan Intermontane Basin went through three phases of wet-dry fluctuations （off-dry）-cold-wet-warm-dry. Since the Middle to Late Holocene， the study area has received less solar radiation in summer， weak evaporation from the North Atlantic sea surface， and low water vapor carried by the westerly circulation； thus， the climate has been arid. In the early Late Holocene， the westerly circulation shifted to the south. The superimposed negative phase of the North Atlantic Oscillation （NAO） transported large amounts of water vapor， and the climate was cold and humid. Then， the climate became warm and dry owing to the increase of solar radiation in the late winter. The abrupt climate change characterized by cold and dry conditions during 4 766-3 601 cal a B.P. was a response to the “4.2 ka B.P.” climatic event， which may have been caused by the weakening of the westerly circulation due to the weakening of solar radiation， the intensification of the cold in the middle and high latitudes， and the lowering of the sea surface temperature in the North Atlantic Ocean.