(Pb1-xBax)ZrO3 (x=0, 0.025, 0.05, 0.075, 0.1) ceramics were synthesized by a traditional solid-state reaction method, and the pure phase was obtained of all sintered samples. For all compositions, substitution of Pb2+ by Ba2+ reduced the phase transition temperature of antiferroelectric to ferroelectric and Curie temperature. Polarization-electric field hysteresis loops were conducted and typical ferroelectric hysteresis loops were observed in higher temperature range. Impedance and dielectric measurements were studied on the high temperature relaxation. Relaxation behavior could be suppressed after annealing treatment in oxygen atmosphere. Value of activation energy calculated from impedance was lower than that calculated from conduction measurements. It was concluded that short-range hopping of oxygen vacancy contributes to the dielectric relaxation and long-distance movement of doubly ionized oxygen vacancies contributes to the conduction.