The soil water characteristic curve and unsaturated hydraulic conductivity gained from seepage tests in Xiajiang reservior area of Jiangxi Province,were fitted by the Van Genuchten(VG)model,and a new multi-component model consisting of plough layer,plough pan,impermeable layer and raising layer was established for the raising-farmland.A three-dimensional saturated-unsaturated mathematical model was also used to simulate the tests based on the parameters of the VG model.The results show that the mathematical model was reasonable and reliable.In addition,the effects of soil compaction and the thickness on the raising- farmland seepage were investigated.A large number of experiments were reduced by the mathematical analysis and the simulated parameters could be used in the engineering design and construction.