The microstructure, piezoelectric and dielectric properties of piezoelectric ceramics (Bi1/2Na1/2)(0.94)Ba0.06TiO3+xwt%MnCO3 (BNBT6-xMn) with x ranging from 0 to 1.5 were studied. X-ray diffraction patterns showed the samples exhibited perovskite structure and Mn additive turned the structure from tetragonal phase to rhombohedral phase. The results of SEM indicated the Mn additive promoted the sintering which was beneficial to the synthesis of the perovskite. With the amount of Mn additive up to 0.1 wt.%, the value of d (33), k (p) ,and epsilon were improved; While Q (m) also was increased until 0.8 wt%. The Mn additive acted on the "soft" and "hard" function simultaneously; When the amount of Mn additive more than 0.8 wt%, the performance drops.