The process of total electron content (TEC) inversion for the ground-based global positioning system (GPS) is presented in this paper. Based on the process, we set up a TEC monitoring system over China using the empirical orthogonal function (EOF) method. The TEC monitoring system is made up of the data transforming module, data processing module, TEC nowcasting module, TEC short-term forecasting module and TEC long-term forecasting module. The system has high autocontrol capacity, high distinguishability and good interaction. The system can quickly obtain and completely analyze the ionospheric TEC. By comparing the results of TEC nowcasting with Global Ionospheric Maps (GIM) of Jet Propulsion Laboratory (JPL), we find that the results of TEC nowcasting and JPL GIM are coherent very well, so TEC nowcasting can better present the real ionospheric TEC over China. This system may have some important meaning for monitoring ionospheric TEC over China and researching ionosphere through TEC.