In this paper, one-dimensional soil-column experiment and its mathematical models were discussed. Due to nonlinear behaviors of solute transport in soil and groundwater, the ordinary retardation factor could be a nonlinear function of solute concentration In this paper, one-dimensional soil-column experiment and its mathematical models were discussed. Due to nonlinear behaviors of solute transport in soil and groundwater, the ordinary retardation factor could be a nonlinear function of solute concentration