The solid solutions of (1-x)Pb(Zr0.56Ti0.44)O3-xBi(Zn0.5Ti0.5)O3 ((1-x)PZ56T44-xBZT) were synthesized via a solid-state reaction method. X-ray diffraction results indicated that the tetragonality of (1-x)PZ56T44-xBZT was enhanced with increasing the BZT content, and a morphotropic phase boundary (MPB) between rhombohedral and tetragonal ferroelectric phases was identified to be in the range of 0.15 < x < 0.18. In addition, the dielectric diffuseness and frequency dispersion behavior were induced with increasing the BZT content, owing to increased disorder degree of both A-site and B-site cations in (1-x)PZ56T44-xBZT perovskite lattice. Contrary to the case in PT-BZT, the increased tetragonality accompanies reduced Curie temperatures (Tc) as PZ56T44 was substituted by BZT. The electrical properties of solid solutions exhibit obviously compositional dependence. The optimum dielectric and piezoelectric properties of epsilon(33) (T) = 1430, d(33) = 365 pC/N, k(p)=50%, Q(m) = 32, and Tc =similar to 260 degrees C were achieved in (1-x)PZ(56)T(44-)xBZT ceramics with x = 0.18 owing to the co-existence of two ferroelectric phases near the MPB.