Smart sensor network with automatic configuration mechanism is proposed and a prototype system is developed. The proposed system consists of three components, smart sensor unit (data acquisition and data management), database (data storage and data management), and MATLAB web server (data analysis and publication). The smart sensor unit is composed of three boards, a micro network terminal called SUZAKU-V, a power supply board and a sensor board. For automatic configuration of the sensor network, the data management system using the star-shape data model and PostgreSQL server is proposed. Using the prototype system, extensive performance tests are carried out, to estimate the maximum number of sensors that can be connected to the sensor network with one server. It turned out that connection of more than 1,000 sensors is possible when cell-based network topology is employed. The developed sensor network has a time synchronization mechanism that assures the accuracy within a few micro seconds.