According to different geochemical behavior between rubidium and strontium during chemical weathering, variations of Rb/Sr ratios in the lake sediment sequence can be used as a good indicator of chemical weathering in watershed. We reconstructed the paleoclimatic change history in the Daihai Lake area during the last 400 years determined by the variations of Rb/Sr ratios in the lake sediment sequence, including the Little Ice Age and two post-glacial rebound. Spectrum analysis shows that the variation of Rb/Sr ratios has quasi periodicity of 100 years, and so does the paleoclimatic change. Combined analysis of magnetic susceptibility, clay minerals and contents yields paleoclimatic records which are more explicit than magnetic susceptibility which has been used as a good paleoclimatic indicator by many researchers.