(Na 0.5 Bi 0.5 ) 1−x Ba x TiO 3 ceramics were synthesized by the citrate method and their structure and electrical properties were systematically investigated. The results of X-ray diffraction analysis revealed a MPB composition range of x=0.06–0.10 for (Na 0.5 Bi 0.5 ) 1−x Ba x TiO 3 system at room temperature. It was found that the piezoelectric and ferroelectric properties of (Na 0.5 Bi 0.5 ) 1−x Ba x TiO 3 compositions near the MPB are rather sensitive to the phase composition and reach preferred values at x=0.07, where the relative content of the tetragonal phase is substantially higher than that of the rhombohedral phases. (Na 0.5 Bi 0.5 ) 1−x Ba x TiO 3 ceramics present a decrease diffusive factor (δ) with increasing BaTiO 3 content, implying a degradation of the relaxor feature and a transition from relaxor ferroelectrics to normal ferroelectrics.