Abstract: A horizontal 2-D numerical model in moving generalized non-orthogonal curvilinear coordinate is established to simulate surges generated by landslide in reservoirs.Comparing with the models using fixed grid,the difficulty in computing the action of the sliding mass on the water body is overcome.Taking a physical model test as an example,the numerical model is used to simulate the change process of the flow,and in the model,the action of the sliding mass on the water body is calculated by the method of variable grid,and the grid covered by the sliding mass slides down along with the sliding mass.Through the comparison between the numerical results and flume test,it is shown that the numerical results are in good agreement with the laboratory data,which indicates that the numerical model with variable grid can simulate the surge process well and offers a new method for computing and forecasting surge generated by landslide in reservoirs.