Abstract: Based on the theory of multiphase flow in porous media, analytical model for NAPL transport in soils is proposed and developed in this paper. Firstly, centrifuge testing and numerical simulation are employed to model the multiphase flow through unsaturated soils, and hence the tempo-spatial distribution and contamination extent are obtained. Then the migration behavior of NAPL in unsaturated soils is analyzed. It is shown that 1) after ground spill, LNAPL enters into unsaturated soils and moves downwards by gravity force, with some retained in pore-S of soil mass; 2) when reaching underground water table, LNAPL floats on it and continues to migrate; 3) hydro-geological condition has significant effect on multiphase flow.