The crystal structure and ferroelectric properties of (1-x) (Bi0.5Na0.5)TiO3-xBa(Zr0.05Ti0.95)O-3 (BNBZTx, x <= 12%) lead-free piezoelectric ceramics were studied. The distance between the centers of cations and anions (d(c-a)) as well as the lattice parameters was carefully investigated by Rietveld refinement on X-ray diffraction patterns. It was found that the crystal phase was determined by the amount of Ba(Zr0.05Ti0.95)O-3 added, whereas the pure rhombohedral and tetragonal phases are observed in compositions containing x <= 4 and x >= 8%, respectively. A rhombohedral-tetragonal morphotropic phase boundary (MPB) was found at around BNBZT6, which showed a maximum and minimum d(c-a) at its rhombohedral and tetragonal phases, respectively. According to the present study, the ferroelectric properties show a strong dependence on their crystal phases. For the single-phase compositions, the remanent polarization (P-r) generally increased with the value of d(c-a) while their coercive fields (E-c) were determined by their lattice parameters. Nevertheless, the behavior in P-r and E-c for MPB compositions is related to not only the lattice parameter but also the composed phases.