Dielectric ceramics are one of the most important electrical insulators because of their excellent electrical stability and nonconducting properties. In this work, new complex perovskite solid solutions, (1-x)Pb(Mg1/2W1/2)O-3-xPbHfO(3) [(1-x) PMW-xPHf] (0.00x0.04), were successfully synthesized in the form of ceramics by the solid-state reaction method and sintering process. The X-ray diffraction results indicate that a single perovskite phase with antiferroelectric (AFE) orthorhombic Pmcn symmetry is formed for x<0.04 which corresponds to the PMW-type solid solution (SS-PMW). For the composition x=0.04, however, a small amount (about 1%) of ferroelectric orthorhombic C2mm phase that arises from the PHf-type solid solution (SS-PHf) was found to coexist with the Pmcn phase (99%). The dielectric measurements show that the AFE-paraelectric phase transition temperature T-C of the (1-x)PMW-xPHf ceramics increases from 38.2 degrees C (x=0) to 40.1 degrees C (x=0.03) with the increasing PHf content, indicating a slightly enhanced AFE ordering degree. The studied materials show a relatively low dielectric constant (similar to 10(2)), a low dielectric loss (similar to 10(-2)), a high breakdown field strength (similar to 140kV/cm), and a linear electric field dependence of polarization at room temperature, which make them a new candidate for potential applications as ceramic insulators.