Two plateau lakes (Lugu Lake and Erhai Lake) with different conditions are selected to show 210Pb geochemical behavior. ²¹⁰Pb and ¹³⁷Cs vertical profiles in sediments are measured by the Multichannel Analysis System (Caberra 100) in order to attain creditable sediment accumulation rates. By the Fe-Mn circulation, ²¹⁰Pb_ex vertical distribution in the sediments of Lugu Lake and Erhai Lake shows three types of distribution characteristics. But this has no influence on the ²¹⁰Pb_ex dating result. Sediment accumulation rates of Lugu Lake and Erhai Lake are 0. 050 -0.051 g·cm a and 0.044 -0.045 g· cm^-2a^-1 respectively by ²¹⁰Pb_ex method which repsents the average sediment accumulation result on 100-year scale. The discrepancy between the ¹³⁷Cs vertical distribution characteristics and the depositional fluxes is probably caused by the Cs diffusion in early-diagenesis process. However, the Cs diffusion does not change the location of Cs peaks. Sediment accumulation rate of Lugu Lake is 0. 045 土 0. 004g · cm^-2a^-1 by ¹³⁷Cs time marker (1964), and that of Erhai Lake is 0. 048 ± 0. 003g·cm^-2a^-1 (1964), 0. 047 ± 0. 002g-cm^-2a^-1(1975), and 0. 046 ± 0. 005g· cm^-2a^-1(1986) respectively which reflects the average sediment accumulation result.