Ancient Lake Ulungur lasted from 33600 cal a BP to 22500 cal a BP and from 16500 cal a BP to 6500 cal a BP with lake level 40 m higher than that of current Lake Ulungur through analysis of AMS¹⁴C dating, grain-size, total carbon and total nitrogen, carbonate content sampled from Ulungur ancient lacustrine sediment profiles around the current Lake Ulungur and through comparison to previous Holocene core lake sediment research results.During late MIS-3 (33600-22500 cal a BP) stage, the climate was relatively warm, ancient Lake Ulungur was in high lake levels and lake sediments transported mainly by river runoff.During Last Glacial Maximum (LGM, 22500-16500 cal a BP), the climate was cold and dry and sources of lake sediments transported by winds.During Postglacial and early to middle Holocene (16500-6500 cal a BP), the climate returned to warm and lake sediments were mainly from runoff again.During the period between 6500-5500 cal a BP, ancient Lake Ulungur shrinked, lake level sharply declined and cores lacked deposits except for the core in the central depression under the influence of high temperature and drought events.And it restored to current status since 5500 cal a BP when the climate turned cold and wet.The records of climatic and environmental evolution of ancient Lake Ulungur were in good accordance with those of adjacent areas.It responded to regional environmental change and global abrupt climate events.Strength and circulation conditions changes between Monsoon and the Westerly and the evaporation effects caused by temperature could be the main causes of regional climate and environmental variation.The study of the sedimentary records from ancient Lake Ulungur can provide geological evidence to ancient large lake evolution in northern Xinjiang and interrelationships between monsoon and the westerly and climate change in their domain areas on long time scales since late MIS-3.