Behavior of pesticide adsorbed on soil and mineral surface is important for determining its environmental fate and risk.The adsorption of glyphosate [N-(phosphonomethyl)-glycine] (GPS;GLY) on six types of soils different in physico-chemical characteristics,and on minerals saturated with metal ions was investigated.The results indicate that the adsorption isotherms were well fitted with the Freundlich equation.Quantity of glyphosate adsorbed on the soils was related to soil characteristics.It increased with the contents of soil clay and Fe₂O₃,but decreased with the increasing soil pH.More glyphosate was adsorbed by kaolinite than by montmorillonite.When the minerals were modified with different metal ions,quantity of adsorbed glyphosate decreased on the minerals,which were in a decreasing order of Fes²⁺-montmorillonite>Ca²⁺-montmorillonite>Na⁺-montmorillonite and Fe²⁺-kaolinite>Ca²⁺-kaolinite>Na⁺ kaolinite.