The higher valence compensation of the Ba 1 − x Bi x (FeTa) 0.5 O 3 (x=0–0.1) system is obtained via a solid-state reaction. The characteristics, including phase formation, microstructure and dielectric properties, are also investigated. In the complex perovskite oxides Ba 1 − x Bi x (FeTa) 0.5 O 3 system, the dielectric constant increases when the Bi 3+ ion concentration increases, because there is an increase in valence compensation dipoles. The dielectric constant Ba 0.94 Bi 0.06 (FeTa) 0.5 O 3 ceramics sintered at 1250°C are about 8×10 4 –10 5 , with a low dissipation factor at temperatures between 273 and 458K and a frequency of 1kHz. The temperature-dependent dielectric constant and loss curves, measured in the temperature range, 273–458K, and at a frequency of 1kHz, indicate that the samples exhibit typical relaxor behavior over a broad temperature range. Complex impedance spectroscopy shows the presence of barrier layers in bi-phase ceramics, which indicates that the orientation and space charge polarization are dominant for Ba 1 − x Bi x (FeTa) 0.5 O 3 dielectric behavior. The frequency dependence of the dielectric loss peak obeys an Arrhenius law, with an activation energy of 0.24eV, and the relaxation time is 10 −9 s.