Since the discovery of relaxor behavior in Pb(Mg-1/3 Nb-2/3)O-3 (referred to as PMN), the studies of relaxor ferroelectrics with Pb(B'B-1/3"(2/3))O-3 type perovskites have intensified because of their excellent dielectric and electromechanical properties. The present study is mainly focused on the quantitative analysis of micro-macro domain transition, using dielectric spectroscopy, hot-stage TEM. The deviation from Curie-Weiss behavior was investigated over a broad range of temperature. As the relative contents of PbZrO3 increased, the Curie-Weiss temperature decreased, while the Curie-Weiss constant increased. However, the Lorentz polarization factor (y) decreased with increasing PbZrO3 content, indicating an enhanced relaxor behavior in the PNN-PT PZ(x) system at higher PZ content. A microscopic examination demonstrates that the relaxor-normal ferroelectric transition corresponds to a micro-macro domain switching. The long-range ferroelectric domains below the transition temperature were characterized by twin-like 90 macro domains with tetragonal symmetry and by the subdomains, which presumably relieves the internal electrostrictive strains associated with the polarization nonuniformity caused by the polar nanodomains.