The objective of the project “Development of Geology GIS for Major River Basins in Taiwan” is to develop a geology geographic information system (GGIS) of the twenty-six major river basins in Taiwan on the basis of the relevant information compiled through a series of GIS projects carried out by the Water Resources Planning Institute up to now. Since the available general information about Touchien River is relative complete, this project hence used Touchien River as an example to illustrate the GGIS in detail and in depth for its contents and possible applications. It is believed that the contents of the Touchien River basin’s GGIS can serve as the blueprint for completing other river basins’ GGIS. The GGIS developed in this project follows the standard format for the GIS systems in Water Resources Agency of Taiwan. All relevant and available geologic information in digital form were collected and included in the GGIS for 26 major river basins in Taiwan. In addition to the GGIS for major river basins, using the Touchien River basin as an example again, this project also studied how the geologic characteristics of a river basin may affect the management and planning of the river and demonstrate several approaches to gather relevant geologic information in a river basin.