The purposes of this project are to investigate the conditions of dam in Taiwan, to list the priority of reservoir renewal improvement, and then to propose the guidelines for action. According the case of dam removal in US, the project has found three reasons (the environmental factors, economic factors, and safety factor) to execute the dam removal. Moreover, many studies demonstrate that the ecosystem would have a positive influence from the dam removal. The study classified the decision-making process of dam removal into the four steps, which were followed by defining the goals and objectives, identifying major issues of concern, being the data collection and assessment, and being decision making. The project was investigated the based information on 70 dams in Taiwan, including the dam forms, dam height, the catchment area, the effective capacity, the functional efficiency and the fishway settings. The project was estimated the operational risk of dam by the method of risk matrix, within three parameters (the degree of sediment, influence of water supply system, and water resources utilization). The predict result showed that five dams would be renewal improvement (Paiho-Reservoir, Agongdian Reservoir, Dapu Reservoir, Luliaoci Reservoir, Teyanpi Reservoir). Finally, the guidelines for action and strategies were established to apply the operation of dam removal on the future.