Two sediment cores retrieved from the enclosed Lake Daihai in the monsoon/arid transition belt of North-Central China were analyzed for major and trace elements and their ratios normalized to Al to investigate the history of changes in the hydrothermal status of the study area based on the chemical weathering intensity (CWI) in the lake basin. As a whole, CWI displays in-phase variations with organic matter (TOC, TN) concentration, carbonate (CaCO₃) content and pollen assemblage that are related to effective monsoon precipitations. Thus high CWI would be associated with strong monsoon-induced precipitation and low CWI with weakened precipitation. The interval between ca.6.7 ka B.P. and 3.5 ka B.P. could be defined as the Holocene Climate Optimum in the region. Changes in the hydrothermal status in the study area during the most part of the last 16.2 ka coincide with the pattern of climate changes in Eastern China. The discrepancies during the interval of ca.9.0～6.7 ka B.P. might be related to the feedback of topography of the lake basin to regional climate changes.