By adding 1.5 mol.% Bi(Mn 2/3 Sb 1/3)O 3 (BMS), (Bi 1/2 K 1/2)TiO 3 (BKT) ceramics show an excellent sintering ability in conventional oxide sintering process. In a wide temperature range from 10201050°C, the 0.985BKT 0.015BMS (BKMS) ceramics demonstrate a super-high relative density of 98% and low dielectric loss tan ¤ of 0.017. Even though the temperature reaches to 1060°C, BKMS ceramics maintain high relative density over 95% other than being collapsed as the pure BKT did. Besides, the BKMS ceramics sintered at 1020 to 1050°C present adequately high electrical properties. The enhanced sintering ability of BKMS ceramics is attributed to the increased viscosity of liquid induced by Sb 5+ solving in the liquid phase during sintering. The work provides a way to realize the densification of BKT ceramics.