Artificial ground freezing method (AGF) is used more and more popularly in underground engineering of soft soil area. However, because of the flaws of freezing theories and the lack of AGF real-time monitoring data, high risk exists in this method. Therefore, it is urgent to set up AGF information systems for freezing construction monitoring and analyzing. According to the special features of AGF and combined with temperature measurement technology, communications transmission technology and computer technology, a network information system for AGF method named GeoFreezer is studied and developed. This system could fulfill the request function of AGF management, including remote, real-time monitoring, visualization, analyzing, and so on. The main hardware of GeoFreezer is composed of advanced digital temperature sensor, “1-wire bus” network, fiber technique, database server, personal computers and so on. Software environment includes Borland Delphi 7.0 as developing platform and Microsoft SQL Server 2000 as database. Client/Server network structure is used for data exchanging and back-up. For the requirement of AGF safety, remote and real-time monitoring is realized and the monitoring rate could be higher than 10 times per minutes. After acquiring data, it could be visualized in kinds of forms such as 2D chart and 3D model, based on which, temperature field, distributing character of frozen soil wall, and the formulas of frozen soil wall characteristics under non-zero freezing temperature are analyzed. The application of GeoFreezer in cross passage construction of Shanghai Yangtze River Tunnel project is specified in the end. The good monitoring performance, safety controlling, and decision-making service proves the practicability and advantage of this system.