The seepage rules of coarse-grained soil are very complicated. The present rational equations just consider some simple facts, therefore it is hard to identify accurate seepage factors. In this article, the coarse-grained soil obtained in Three Gorges Reservoir area is used to calculate the seepage factor of different graduation through the experiment, which is predicted through the powerful nonlinear and dynamic dealing capacity of the neurotic network. As a result, the influence of different graduation of the coarse-grained soil is taken into account. Through a comparison between the prediction from neurotic network and the experimental results, and the former can be used to predict the seepage factor of coarse-grained soil and this method can reflect the influence of different graduations.