CaCu3Ti4O12 (CCTO) ceramics doped with different proportions of Sc2O3 dopant (mol%, x=0, 0.05, 0.10, 0.15 and 0.20) were prepared by the traditional solid-state reaction method.SEM and XRD were used in the microstructural studies of the specimens and the electrical properties were investigated.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 slightly decreased the dielectric loss.A high dielectric constant and low dielectric loss can be achieved when the optimum doping concentration is 0.10 mol%.