Tóm tắt: In this paper, in order to achieve a type of material with mixing “soft” and “hard” properties for piezoelectric transformer applications, polycrystalline ceramics of PbZrO3 – PbTiO3 – Pb[(Mn1/3Nb2/3)x(Sb1/2Nb1/2)1-x]O3 (PZT-PMnSbN), x = 0.4; 0.5; 0.6; 0.7; 0.8; 0.9; 1.0, having a rhombohedral perovskite structure have been synthesized by the Columbite precursor method. Scanning electron micrograph (SEM) shows the compactness of the sample and the average grain size was found about ~ 1.89 µm. The electromechanical coupling factor (kp), piezoelectric constant (d31), mechanical quality factor (Qm) of PZT-PMnSbN composition ceramics with x = 0.7 showed the optimal value of 0.6, 180 pC/N, and 1895, respectively, and spontaneous polarization Pr  49.2µC/cm2 were observed at room temperature. These values indicated that the newly developed composition may be suitable for piezoelectric transformer applications.