Perovskite solid solution ceramics of PZN–PT–BT with several compositions were synthesized by solid-state reaction method. X-ray diffraction results indicate pure perovskite structures for all samples. Dielectric measurements show that the implicit Ba(Zn[Formula: see text]Nb[Formula: see text])O₃(BZN) composition could broaden the diffusion phase transition (DPT) peaks and lower the [Formula: see text] and [Formula: see text] values. The observed dielectric properties may be caused by the increased cation disorder due to the substitution of barium onto the A-site and titanium onto the B-site.