Watershed is a unique natural unit from either the geomorphologic, meteorological, or hydrologic point of view. Therefore, for the integrated management of all water related resources with multi-dimensional objectives, watershed is the most convenient unit for consideration. In this study, the design and construction for the database of a Geographic Information System is performed for Toa-Cheng watershed, located in Hsin-Chu, Taiwan. Taking examples from other countries, and based on the current mandate of the Water Conservation Bureau, the database is categorized into the GIS environment and the detailed database. In the GIS environment category, metadata for various geographic related data sources are identified and compiled. For the detailed data, the base map together with several layers with different attributes, is established for practical applications.