Reservoir safety is always the key and difficulty of flood prevention. The safety of the flood season of small and mediumsized reservoirs has become a weak link in the current national flood prevention work. As the state investment of water conservancy industry gradually increases, small reservoirs water level, rainfall and other monitoring equipments have been installed in the most reservoirs of small and medium sized reservoirs in our province , and dam seepage pressure, seepage flow and other automatic monitoring equipments have been installed in a part of small reservoirs. To realize the automatic monitoring and visualization management in the reservoir areas such as rainfall volume, water level,dam seepage pressure, seepage flow, seepage lines,the timely, accurate and intuitive information can be provided for the safety management and operation of these reservoirs.Based on the network of geographic information system (WebGIS) technology, Jiangxi Provincial Water Resources Department designed and developped the safety management information system of small and medium sized reservoirs.