The present paper is to inyestigate the rate and process of arsenate adsorption and desorption,and the energy of arsenate adsorption by some soils in Shaangi Province.A two-constant rate equation (C=k·C₀·t^1/m)developed by Kuo and Lotse is better than five equations,i.e.firstrorder reaction,second-order reaction,third-order reaction,parabolic diffusion and the elovich equations used for fitting the experimental data.Sectionally fitting by two-constant rate equation can further improve the goodness of fit.The activation energy of adsorption calculated according to the Arrhenius equation was 0.7-34 kcal/mole.The relatively low activation energy suggests that adsorptian of aasenate in the soils might probably be a physical process,which obviously dffifens from the chemical reaction in true solution.The rate and capacity of adsorption and desorption by soils are affected by incubating time,temperature,ratio of solution and soil,concentration and amount of As added,and soil characteristics.Clay soil has a higher adsorption rate constant (k),and higher adsorption amount than sandy loam.But the sandy loam has a higher desorption rate constant (k_-1),so arsenate is more easily released from soil into solution.