Lead-free piezoelectric ceramics (1 - x)Bi-0.5(Na0.84K0.16)(0.5)TiO3-xBa(0.77)Ca(0.23)TiO(3) (BNKT-xBCT, x = 0-0.04) were synthesized by conventional solid-state reaction method. The piezoelectric, dielectric, and ferroelectric characteristics of the ceramics are investigated and discussed. The XRD results show that Ba0.77Ca0.23TiO3 (BCT) has diffused into Bi-0.5(Na0.84K0.16)(0.5)TiO3 (BNKT) lattices to form a new solid solution. It is shown that moderate additive of BCT (x a parts per thousand currency sign 0.025) in BNKT-xBCT ceramics can enhance their piezoelectric and ferroelectric properties. Three dielectric anomalies are observed in BNKT-xBCT (x a parts per thousand currency sign 0.03) ceramics. The piezoelectric measurements and P-E hysteresis loops reveal that BNKT-0.025BCT ceramic has the highest piezoelectric performance and strongest ferroelectricity in all the samples. Piezoelectric constants d (33), k (p,) and k (t) of 175 pC/N, 29.1, and 54% are, respectively, achieved. Remnant polarization P (r) and coercive field E (c) reach 28.3 mu C/cm(2) and 24.2 kV/cm, respectively.