This paper was an attempt to use the ¹³⁷Cs mass balance model for assessment of recent deposition rates in Lake Qinghai.¹³⁷Cs concentration peak at the depth of a few centimeters in the deposit profiles of Lake Qinghai and other lakes with lowerdeposition rates may be caused by the nuclide downward diffusion and migration progresses after the ¹³⁷Cs deposited on the surfaceof lake bottom mud. Therefore, the interpretation of the sediment layer at the ¹³⁷Cs peak depth depositing in 1963 and the calculationmethod of sediment deposition rates under that assumption may not be reasonable. Local¹³⁷Cs reference inventory was117.7mBq/cm² in 2005 obtained from grass land of the flat lakeside. ¹³⁷Cs inventories of the six lake sediment cores collected fromthe Island Hill of the center of Lake Qinghai to the Fish Port in the south-eastern lake ranged from 92.9mBq/cm² to 325.0mBq/cm². Itwas clear that sediment deposition apparently occurred in the south-western part of the lake, particularly, the deposition is quite fastat the QHH02 Core position, which is located in the front of the underwater alluvial fan. However, sediment deposition was very slowat the centre part of the lake. The average ¹³⁷Cs concentration of the deposited sediments in Lake Qinghai since 1963 was estimated tobe 30mBq/g by analyses of the ¹³⁷Cs concentrations from the lake mud in surface layers, the sediment discharged from inlet rivers,and the soil in surface layers on the grass land in the catchment. The average deposition rate in the centre of the lake was 0.020cm/acalculated by the ¹³⁷Cs mass balance model, which agreed to 0.018cm/a of the specific sediment yield of the Buha River, but muchlower than the reported deposition rates estimated by conventional dating techniques. The deposition rate of the QHH02 Core was0.229cm/a, suggesting that the deposition rates in the south-western part of the lake were much higher than the rates in the centre partof the lake and which was twice of the reported deposition rate of Lake Qinghai.