Abstract: The pore pressure dissipation in the loam core of earth and rockfill dam at Bikou Hydropower Statiou is analysed with element difference method and finite element method. The nonlinear relationships of initial pore pressure coefficient B, between Bf and Bo, and normal stress are given. According to the preliminary observed data by the piezometer, computed pore pressure values at the end of construction, taking account of arching effect in the core, fairly correspond to these field data and the given value B is feasible in computation.