Interactions between charged soil clay particles and cations in the field of energy has long been a subject attracting all soil chemists.Efforts are made to introduce equations for calculating mean free binding energy and mean free adsorption energy between cations and charged soil clay particles and the application of Wien effect in dilute suspensions, to the study on energy relationships between cations of K⁺, NH₄⁺, Ca²⁺, and Cd²⁺ and clay particles of yellow-brown soil, brown soil, and black soil.Results show that 1) mean free binding energies between cations of K⁺, and NH₄⁺ and the clay particles are in the range of 6 3~ 7 1 kJ mol^-1, and slightly higher with K⁺ than with NH₄⁺; 2) mean free binding energies between ions of Ca²⁺, and Cd²⁺ are in the range of 7.2~ 9.4 kJ mol^-1.With the same cation, the soils follow the order of yellow-brown soil< brown soil< black soil in binding energy.The mean free adsorption energies, ΔG_ad, of the four cations with the three soils under the same high field strengh, e.g., 150 kV cm^-1, show that the values of K⁺ and NH₄⁺ are quite close in yellow brown soil and brown soil, being 0.9 and 0 8 kJ mol^-1, respectively; but in black soil, the value of NH₄⁺ is higher than that of K⁺ by 0.1 kJ mol^-1.The adsorpt ion energies of Ca²⁺ in yellow-brown soil and black soil are 0.3 and 0.6 kJ mol^-1 higher respectively, than that of Cd²⁺.The adsorption energies of divalent cations are 1~ 1.5 times higher than that of monovalent cations.