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Lakes are not only the critical natural resources on the earth, but also key indicators of local and regional watershed changes, making them useful for detecting Earth's response to climate change. More than 1000 closed lakes having stood much higher than now decorate the Third Pole, i.e., mainly Tibetan Plateau (TP), and yet the timing and duration of their past expansions and hence climate forcing that sustained large hydrologic variations remain unclear particularly for the late Quaternary. Well-preserved shorelines located 100s of meters above present lake levels are widespread in the lake basins over TP, allowing to reconstruct the past hydroclimate changes according to age control of palaeoshorelines. Previously, single aliquot (SA) luminescence methods of both quartz and K-feldspar fractions have been extensively utilized for dating of the lake-level related sediments, but very few considered the issue of partial bleaching which often occurred especially for the water-lain sediments from TP [1,2]. Because it is quite difficult to evaluate the bleaching level of sediments with SA, in which many grains are measured simultaneously, causing averaging effects, and any variability in resetting between grains will be masked [3]. With the development of measurement protocol and facility, it becomes very feasible to determine the luminescence signals from single grain (SG), able to improve the reliability of ages by explicitly assessing the bleaching condition of sediment sample. In this study, we applied the SG K-feldspar technique with post-IR IRSL (pIRIR) protocol to build up the chronologies of a set of selected palaeoshorelines from the two largest lakes, Qinghai Lake from the north TP and Selin Co from the south TP, with aims: (1) to choose which thermal treatment is the most suitable for K-feldspar SG dating of the late Quaternary shoreline sediments over TP; (2) to verify if the relevant sediments were bleached sufficiently or not before deposition; (3) to constrain the timing of late Quaternary lake expansion based on SG data, and compare with previous SA data; (4) to assess asynchronous evolution pattern for the lakes from the north and the south of TP. [ABSTRACT FROM AUTHOR]