CaCu3Ti4O12 ceramics doped with different contents of Sc203 (mol%, x = 0, 0.05, 0.10, 0.15, and 0.20) were prepared by the traditional solid-state reaction method. Scanning electron microscope (SEM) and X-ray diffraction (XRD) were used in the microstructural studies of the specimen, and the electrical properties were inves- tigated. XRD results show that the Sc has no influence on the phase composition. The results from the dielectric measurements show that further increase of Sc doping could decrease the dielectric loss slightly. A high dielectric constant and low dielectric loss can be achieved when the doping concentration is 0.10 mol%.