A series of Ba-0.94(Bi0.5K0.5)(0.06)Ti0.85Zr0.15O3 (referred to as BBK) ceramics with high density microstructure were fabricated by a two-step sintering method. A strong influence of the sintering temperature on the microstructure, dielectric properties and relaxor behavior of BBK ceramics was observed. Slim hysteresis loops could be obtained in all BBK ceramics, and the optimal sample sintered at 1250 degrees C for 6 h shows a high dielectric constant (epsilon(r) (similar to)3066 at 10(2) Hz), a low dielectric loss (tan delta (similar to)0.005 at 10(2) Hz), a high energy density (W-discharge (similar to)0.95 J/cm(3) at 76 kV/ cm) and a high energy efficiency (eta (similar to)88% at 76 kV/cm). The correlation of electrical properties for BBK ceramics with sintering temperatures could be attributed to grain size effect and relaxor behavior.