DEM(Digital Elevation Model) is the digital representation of earth surface,which is used for enormous applications.Generally,DEM is employed without the analyses of its effects of both uncertainty and propagations on specific applications.In this paper,the effects of DEM uncertainty on the selected topographic parameters,such as the slope,upslope contributing area,the topographic index and TOPMODEL hydrological model,are analyzed in terms of the DEM uncertainty propagation.Furthermore,the effects of DEM uncertainty propagation on three topographic parameters are evaluated by using the simulation method of Monte Carlo,and then the effects of DEM uncertainty propagation on TOPMODEL is analyzed in the quantitative and qualitative aspects.This research shows that DEM uncertainty propagation almost certainly affects the slope,upslope contributing area and the topographic index as well.Among all of them,its effect on upslope contributing area is the biggest; while on the topographic index is the smallest.However,the effect of DEM uncertainty propagation on TOPMODEL is trivial and could be ignored in the applications.Further,the reasons can be found that on the one hand,the TOPMODEL is not sensitive to the distribution of topographic index; and on the other hand,the topographic index is affected limitedly by DEM uncertainty propagation.