Selecting Anlan Town,a Banan District of Chongqing as the research scope,based on the large scale topographic map data,this paper utilizes the unit of 50m × 50m grid size to extract the digital elevation model (DEM).By the ArcGIS hydrological analysis module,according to the DEM depressions’ filling and the simulation of the direction of flow,each grid cell’s flow accumulation is determined,and in accordance with this flow accumulation,a reasonable threshold is set to extract river,then,according to the data of the direction of flow,Alan Town’s 110 small watersheds are obtained.On the other hand,on the basis of Alan Town’s history flood disaster statistics,taking the town’s 110 small watersheds as statistical unit,using the spatial overlay analysis and the interlinkage of property sheet,the distribution of each statistical unit’s disaster point is located.Finally,by the spatial statistical analysis toolbox,the disaster’s density distribution of Alan Town is abtained.The analysis results show that this town’s high risk disaster point’s density is 1.1802.341 (a / km2),and the area is 11.89 km2,which is accounted for 9.73% of the total area of Alan town.This analysis is in line with the actual situation of this area,and the division of this basin is relatively reasonable.