The watershed-subwatershed-hydrological response units discretization scheme were designed in the study area of Lianshui basin, Xingguo County, Jiangxi Province. Supported by RS and GIS. The method of distributed hydrological modeling based on raster Digital Elevation Models (DEM) was applied to generate basin network, to divide subwatershed and generate basin boundary automatically. The subwatershed discretization divides the watershed into subwatersheds based on the topographic features of watershed, and each subwatershed can be farther portioned into multiple hydrologic response units (HRUs) which are unique soil/land use combinations within the subwatershed and modeled through statistical spatial overlay analysis. At last 62 sub-basins and 399 hydrological response units were produced in the study area and spatial discretization of the basin were successfully realized. A series of technological problems such as the accurate generation of basin network in plate area and error correction of basin boundary were solved in the research process.