Abstract: The adsorption of Cs(Ⅰ) on Taohuajiang sediments was studied as a function of contact time, solid-liquid ratio, pH, ionic strength, temperature, Cs(Ⅰ) concentration and mineral composition. It is found that Cs(Ⅰ) adsorption is sensitive to ionic strength and the content of clayey components in sediment, whereas it is insensitive to pH and temperature, indicating that Cs(Ⅰ) adsorption mechanism is cation exchange on clayey components. The desorption rate of Cs(Ⅰ) on Taohuajiang sediments is obviously lower than the adsorption rate. In the framework of the frayed edge-planar site conceptual model available in the literature, a new adsorption model was constructed to interpret quantitatively the adsorption of Cs(Ⅰ) on Taohuajiang sediments. The study results are useful to accurately predict the adsorption of Cs(Ⅰ) on the Taohuajing sediments, and provide basic data and reference model for the assessment of water quality around Taohuajiang Nuclear Power Plant, the establishment of wastewater discharge standards and the emergency treatment of nuclear accidents.