The Tibetan Plateau is the key to understanding the East Asian and Indian summer monsoons because of (i) its role in initiating and maintaining monsoon circulations and (ii) its high sensitivity to monsoon variations.One related question is how long-term chemical weathering processes respond to monsoon change.As bivalved arthropods, the chemistry of freshwater ostracod shells provides valuable information about lake water chemistry.Due to distinct difference between the 87Sr/86Sr ratios of seawater and freshwater, the stratigraphic 87Sr/86Sr variations of ostracod fossils have been successfully used to trace the transitional marine-lacustrine environment.However, only one work has focused on ostracod 87Sr/86Sr ratios to evaluate changing conditions in a truly lacustrine or freshwater system.We provide the first coherent, high-resolution chemical and ostracod Sr-O isotopic records of early to mid-Pleistocene climate variations and chemical weathering processes related to changes in the Indian monsoon system from the central Tibetan Plateau.