The classical one-domain model with convection-dispersion equation was used in this study for describing a nonreactive solute transport in soil.By the experimental studies on the effect of soil aggregate size and pore water velocity on the transport of nonreactive solute in soil column,it was found that:tritium breakthrough curves could be well predicted by convection-dispersion equation;with the increase of aggregate size,early breakthrough,tailing and small peak were more pronounced by tritium breakthrough curves in soil column,best fitted D value increased as well;and D was proportional to pore water velocity in this study,and dispersion increased with the increase of pore water velocity,which is of great importance for studying the transport of reactive solute in soils and for predicting the fate of agricultural chemicals in field conditions.