Abstract: The Ningbo hydrogeological monitoring well network is a national underground water monitoring project which is established by former Ministry of Land and Resources and Ministry of Water Resources together. As a key construction part of national underground water monitoring project （Zhejiang part）, its major purpose is to monitor the quality of water environment, to protect geological environment, and to provide a solid foundation for geological management, protection, and decision-making. Currently, there are 146 underground monitoring wells in Ningbo, with 36 deep confined water wells, and will reach 161 after recent expansion. This confined well network is characterized by reasonable structure, clear stratigraphic column and detailed well-forming report. According to the requirements of seismic fluid observation, this network can be selected as the fluid observation network.