(1-x)CaCu3Ti4O12-xCeO2　(x=0.1,　0.2,　0.3,　0.4)　and　CaCu3Ti4O12　ceramics　were　synthesized　through　a　solid-state　reaction　technique.　X-ray　diffraction　indicates　that　the　CaCu3Ti4O12　phase　is　formed　in　all　ceramics.　SEM　micrographs　show　that　the　grain　size　of　ceramics　declines　with　the　addition　of　CeO2,　which　is　attributed　to　the　solute　drag　effect.　When　the　addition　amount　of　CeO2　is　0.4,　the　ceramic　obtains　the　maximum　dielectric　constant　at　low　frequency.　Increasing　the　composite　content　of　CeO2　can　effectively　reduce　the　dielectric　loss　of　CCTO　ceramics　at　high　frequency.　And　the　lowest　value　is　0.1　when　the　addition　amount　of　CeO2　is　0.3.　Impedance　analysis　shows　that　the　lowest　dielectric　loss　obtained　for　the　ceramic　is　due　to　the　lowest　grain　resistance.　©　Published　under　licence　by　IOP　Publishing　Ltd.