Abstract: SORPTION AND DESORPTION OF RADIOSTRONTIUM AND RADIOCESIUM ON CALCAREOUS SOILDu Jinzhou;Dong Wenming;Ding Guozhu;Tao Zuyi(Department of Modern Physics，Lanzhou University，Lanzhou 730000) Fan Zhongxiu(Lanzhou Agriculture School of Gansu Province，Lanzhou 730020)Abstract: Sorption and desorption isotherms of radiostrontium and radiocesium on the untreated calcareous soil and three treated soils are determined by batch method at 20 ℃，pH=7．8±0．2 and in the presence of 1mmol／1 CaCl_2．The calcium carbonate and the organic matter are removed by HAC-NH_4AC and 30％H_2O_2 treatments respectively，and both the solid components are removed by the sequential treatments.The effect of different components on the retention of Sr and Cs is investigated.Keywords: Radiostrontium Radiocesium Sorption Desorption Calcareous soil