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Manas Lake is a closed lake basin in northern Xinjiang Province of China, with its current lake bed at 244 ma.s.l. Sediments from the lake area provide valuable information about the paleoenvironmental changes in the Westerlies-dominated arid region. To obtain a chronological constraint on the past changes, optically stimulated luminescence dating was conducted on sediments from the lake beaches. The results show that lacustrine episodes dated at similar to 80-73 ka ago were recorded in northwestern side of the lake at 270 ma.s.l., while paleoshoreline to near-shore environments during similar to 8090 ka ago were recorded in the opposite side of the lake at 262 ma.s.l. The similar to 80 ka old sedimentary layers are overlain by paleoshoreline sediments formed within the last similar to 1 ka, separated by a large age gap. From this study and the results from previous studies, it is concluded that breaks in sedimentary records are common in the lake area at elevation > 260 ma.s.l. When comparing sedimentary environments at different times from different sites in this study and previous studies, it is suggested that a small amount of uplift of the northwestern side of Manas Lake relative to the southeastern side may have occurred in the last 80 ka.