Ni-particle-dispersed (Ba0.95Ca0.05)(Ti0.96Zr0.04)O-3 (BCTZ/Ni) piezoceramic composites were prepared via sintering at 1300 degrees C in industrial N-2 gas. structural characterizations showed that the metallic Ni was not oxidized and the BCTZ preserved the perovskite structure. The Ni particles were uniformly distributed in the BCTZ ceramic matrix. The relative dielectric constant Er of the BCTZ/Ni composites increased from 1362 to 3910 with increasing Ni content from 0 to 20 vol.%, which is explained by the Maxwell equation as well as the micro-capacitor model. The percolation theory of insulator-metal transitions is also applied to correlate the rapid increase of dielectric constant with Ni content. The piezoelectric constant d(33) gradually decreased from 230 to 50 pC N-1, giving a gradient profile of piezoelectric property. We demonstrate that the electrical properties can be effectively tailored by dispersing metal particles into piezoceramics. (C) 2010 Elsevier B.V. All rights reserved.