Abstract: A 3-d, numerical refined model is developed for simulating seepage flow through RCC dams. In the model the rational modelling of the seepage characteristics and the seepage control effectivenesses of the lift joints, the drainage holes in dam, the gallery openings, and the relief wells in foundation are more exactly presented. According to the given design and construction conditions of the dam No.1 on the Niu-ri Creek, 27 schemes of seepage flow control are calculated and the results are interpreted in detail. Finally, recommendations for design and construction of the seepage flow control are given.