Abstract:The Green Ampt infiltration model is extensively applied in many aspects, and a common means used for simu lation of rainfall infiltration and stream production on slope. Average potential suction Sf and general saturation water conductivity Ks are key parameters of this model. In this paper the mean water content increment Δθ(t) in wetted zone during ponded infil tration was defined. A ponded infiltration experiment was carried out on brown earth in Yantai, indicating Δθ(t) was a constant of 0.34. The relation between general wetting front and actual wetting front was quantified based on the water balance principle, and methods of determining Sf and Ks were put forward on the basis of the relationships of infiltration rate i(t) with cumulation infiltration I(t) or with actual wetting front Zfa in graphic characteristics. Compared with the field data, the calculation of infil tration rate and accumulation infiltration based on graphic characterization of i(t)~I(t) and i(t)~Zfa was relatively high in accuracy with overall relative error being less than 6%.