Temporal variations of ionospheric electron-density (IED) distributions over China are inversed by applying the computerized ionospheric tomography (CIT) technique to dual-frequency GPS data of the Crustal Movement Observation Network of China (CMONOC) in 2003. Characteristics of the diurnal variations of IED, especially the development and disappearance of the equatorial anomaly structure and the variations of the ionospheric vertical structure, are investigated. The result shows that it is feasible to sound and investigate the temporal-spatial variations of IED by using CIT technique and the high-accuracy GPS data, but the accuracy and reliability are limited by insufficiency of GPS data, reconstruction methods, and CIT models.
