Characteristics of NH₄⁺ transport during water infiltration and redistribution have been studied with the soil column destruction method.The solute distribution curve in the soil profile (depth vs. amount of solute retained in per gram dry soil) was of slope at the beginning of infiltration,and its upper part gradually became vertical to the abscissa while infiltration continued.Compared with water in infiltration and redistribution,solute was significantly delayed.The ratio of water wetting front depth to solute front depth,indicating the delay of solute infiltration,increased with the process of infiltration.With increasing concentration of displacement solution,the solute retardation factor during infiltration decreased and the velocity constant of soil NH₄⁺ retention reaction increased,accordingly,the apparent Gibbsfree energy decreased.Solute redistributed while water was redistrbuting. The solute amount retained in per gram dry soil at the iso-concentration point of solute redistribulion,which was the cross point of solute distribution curves of different times,was not changed during solute redistribution.In the upper part of the soil column above the iso-concentration point,the solute amount retained in per gram dry soil decreased,contrarily that in the lower column part increased due to solute redistribution.The depth of the iso-concentration point increased with increasink concentration of the displacement solution.