Phosphate adsorption capabilities of different natural palygorskites and iron modified palygorskites in water with different phosphate concentrations were investigated, and the mechanisms of phosphate adsorption of natural and iron modified palygorskites were also studied through adsorption isotherms and adsorption kinetics experiments. The results show that the three palygorskite clays have different kinds of performance on removal of phosphate. For water quality o f Grade Ⅴ and lower than Grade Ⅴ, the more dolomite they contain, the higher removal efficiency they have. The iron modification treatments increase the phosp hate adsorption capabilities of natural palygorskite. The phosphate adsorption isotherm of natural palygorskite is an S-type isotherm, the Freundlich equation (R2=0.977 6) provides better fitting than the Langmuir equation (R2= 0.924 9) in terms of R2 values, suggesting that the adsorption of phosphate on palygorskite is inhomogeneous multilayer adsorption. On the basis of R2 values, the kinetics of phosphate adsorption on the palygorskite can be satisfactorily described by the pseudo-first-order equation, power function equation, parabolic diffusion equation and pseudo-second-order kinetic equation. However, the phosphate adsorption isotherm of iron modified palygorskites is an L-type isotherm, the Langmuir equation (Fe2+: R2=0.96, Fe3+： R2=0.967 7)provides better fitting than the Freundlich equation (Fe2+: R2=0.965 7, Fe3+： R2=0.936 1) in terms of R2 values, implying that the adsorption of phosphate on iron modified palygorskite is homogeneous monolayer adsorption. The results obtained reveal that, as the surface charges and adsorption activity sites of palygorskite are changed by iron modification, so do the phosphate adsorption mechanisms.