Abstract: The finite element method is adopted to analyze the horizontal joints of BAKUN concrete faced rockfill dam, the behavior of rockfill and the soil-structure Interface are described by using Shen’s two-yield surfaces model and the Tsinghua elasto-plasticity damage model respectively in this paper. Concrete’s stress and deflection were given with various horizontal joints numbers and width, also their distribution law. Basically，the arrangement of horizontal joints has no effect on the stress and deformations of the dam; the number of horizontal joints has little influence on the deflections of the concrete face; slope-direction stress homogenizes with the increasing number of horizontal joints, the maximum has the tendency of reduction; slope-direction stress decreases with the increasing concrete faced horizontal joints width, but the effect is not distinct; slope-direction stress will be minished with the increasing width between the concrete face and defend wave wall.