Digital Elevation Model (DEM) is an important parameter to build a distributed hydrological model. In this paper, A SWAT hydrological model for the upstream of the Minjiang River was constructed, and the impact of spatial resolution of DEM on hydro - logical characteristics extraction and runoff simulation was analyzed. The results show that the lower DEM spatial resolution will lead to lower peak flow simulation accuracy, bigger error between simulated and measured flow. When spatial resolution of DEM decreases from 25m to 200m, the accuracy of simulation will decline a little, and when spatial resolution decreases from 200m to 3200m, the accuracy of simulation will decline significantly. In addition, the impact of DEM spatial resolution on runoff of simulation is not significant.