Abstract: The two-dimensional seepage analysis of the valley type tailings pond did not take into consideration the dam axial dimensions， which leads to a high saturation line in calculation with more dangers. The three-dimensional calculation is more realistic， but it consumes more time and labors. In order to solve this problem， a new method for seepage calculation of tailings pond is proposed. This method selects the boundary feature points and the internal feature points in the two-dimensional modeling of the tailings pond， and the axial dimensions of these points are used in the calculation by interpolation. The calculation results show that the obtained saturation line is close to the three-dimensional result， which can reflect the real situation of seepage to a certain extent. With simple operation and clear principle， this method has a certain practical value.

Key words: Tailings dam, Seepage, Saturation line, Autobank, Axial dimension