Abstract: On the basis of experiment measured hydrodynamic parameters on Guilin and Liuzhou lateritic soil, the solute transport process of the two lateritic soils are analyzed, for the purpose of indentifying the effect of hydrodynamic parameters. The results show that Guilin lateritic soil, which contains more quartz, exhibiting higher volume water content and lower hydraulic conductivity at the same suction, has better water holding capacity than Liuzhou lateritic soil. According to the solute transport theory, the 1-D concentration distributions in the two lateritic soils are simulated at four level of initial saturation 95%, 90%, 85%, 80%.With the initial saturation decreasing, solute diffusion depth of Liuzhou lateritic soil increases, while diffusion depth of Guilin lateritic soil become small at the 85%saturation, indicating the relationship between diffusion depth and initial saturation in Liuzhou lateritic soil is not applicable to Guilin lateritic soil. The process of seepage in unsaturated soil is controlled by the dual factors of suction and permeability. For Guilin lateritic soil, its low permeability becomes major governing factor as the saturation decreasing because the reduction of permeability surpasses the increases of suction gradient, resulting in the velocity of fluid. However, the hydraulic conductivity of Liuzhou lateritic soil has small change with the variation of initial saturation, indicating the unsaturated seepage dominated by suction gradient.