Two conventional river - channel storage - volume calculation methods have following shortages: a few parameters can be used, and results are not accurate and cant be visualized. The river - channel storage - volume calculation on DEM is a new calculation method. The calculating steps are as follow s: First, pick - up elevation data about the lines and points on a vector river topographic map to construct a rivers digital elevation mode l; Then, give calculation conditions; At last, calculate the river - channel storage - volume on the theory of DEM. Using the method to calculate can not only obtain more accurate results, but also can realize river - channel storage - volume 3D visualization and view the distribution of the river scouring - silting.