Ce-doped BaTiO3-based ceramics were prepared and studied to satisfy ultra-broad temperature stability (from −55°C to 300°C, capacitance variation rate based on C20°C is within ±15%). The sample with 0.6 mol% CeO2 succeeds to achieve this performance with a remarkably high ceiling temperature of 300°C. Meanwhile, the sample has good dielectric and electrical properties at room temperature (εr = 1667, tanδ = 1.478%, ρV = 5.9 × 1012 Ω·cm). Ce ion can substitute for Ti ion as Ce4+ or Ba ion as Ce3+. The substitution decreases the spontaneous polarization of BaTiO3, and then weakens the ferroelectricity of BaTiO3. As a result, the temperature stability of samples is improved obviously. Besides, CeO2 addition promotes the formation of exaggerated grains, which are consisting of Ba6Ti17O40.