In this study, piezoelectric and dielectric properties of Lead-free 0.97[(K0.5Na0.5)(Nb0.97Sb0.03)O3] + 0.03[(Bi0.5K0.5)TiO3] (abbreviated as 0.97NKNS-0.03BKT)ceramics synthesized by conventional solid-state reaction process were investigated as a function of K5.4Cu1.3Ta10O29 addition. The results indicated that the K5.4Cu1.3Ta10O29 addition significantly improved the sinterability, grain growth and piezoelctric properties of 0.97NKNS-0.03BKT ceramics. The optimum values as planar piezoelectric coupling coefficient (kp= 0.355), piezoelectric constant (d33= 207 pC/N) and mechanical quality factor (Qm= 128) were obtained when 0.009KCT was added. The electromechanical coupling factor(kp )was slightly decreased according to the increasing temperature.
