In this study, K2CO3,Bi2O3, BaTiO3, and TiO2were mixed to form the compositions of 0.65 K0.5Bi0.5TiO3-0.35 BaTiO3+ x wt% Bi2O3(abbreviated as 0.65 KBT-0.35 BT3-x, x = 0, 1, 2, and 3). Excess Bi2O3was added into the 0.65 KBT-0.35 BT3 composition as the sintering aid to lower sintering temperature, to improve densification, and to compensate the vaporization of Bi2O3 during the sintering process. After being calcined at 850 °C for 2 h, 0.65 KBT-0.35 BT3-x ceramics were sintered at 1050 °C∼1100 °C in air for 2 h. The X-ray diffraction pattern and scanning electronic microscope observation were used to analyze the variations of crystalline phase and microstructure of the 0.65 KBT-0.35 BT3-X ceramics. Temperature-dependent dielectric characteristics were measured with oscillating amplitude (50 mV) at 100 KHz by an HP4294A impedance analyzer by putting the sintered ceramics in a temperature-programmable testing chamber from 25 °C to 500 °C. We would well investigate the effects of sintering temperature and excess Bi2O3content on the maximum dielectric constant and Curie temperature of the 0.65 KBT-0.35 BT3-x ceramics.