【英文摘要】To study the climate instability at millennium timescale under the background of the glacial-interglacial cycles for mid-latitude of northern China, this project has investigated an 80-m core drilled at lake shore of the Daihai Lake in central Inner Mongolia and a late Pleistocene loess profile from Jingyuan, Gansu. Geochronological and multi-proxy measurements have been focused on the time interval equivalent to the marine isotope stage 3 (MIS3, 60-28 ka). Optical dating experiments led to a chronological framework for the 80-m core with the base dated to about 150 ka, Severe optical age underestimation was observed in the loess of Jingyuan and a new protocol was developed to circumvent this problem, leading to a high-resolution chronology for the profile and comparison with the dust records from polar regions. C-14 measurements on modern samples around the Daihai Lake, combined with water chemistry analysis, confirm the hard-water effect is the main cause for the uncertainty in the radiocarbon age of Daihai lake samples. A preliminary comparison of the palynological, magnetic, reflectance spectrophotometric and sedimentological analyses reveals no coherent variability, suggesting that rapid environmental changes during MIS3 around Daihai Lake area were complicated than recorded in other archives. Given the locality of the drilling site, our results indicate that lake areas in the mid-latitude of northern China were not significantly reduced, which may be related to the shift of the precipitation pattern during the last glacial time.