Na 0.5 Bi 0.5 ) 1−x Ba x TiO 3 (x =0-0.12) powders were synthesized by a citrate method, and the structure and electrical properties of the resulting ceramics were investigated. A gradual change of crystal structure with the increase of BaTiO 3 concentration was detected together with a significant evolution in grain size and shape. A rhombohedral-tetragonal morphotropic phase boundary (MPB) near x=0.06 at room temperature was ascertained for the ceramics. The dielectric constant (ɛ r ) and dissipation factor (tanδ) attain maximum values at x=0.08 and x=0.06, respectively. The specimen of x=0.06 provides the maximum piezoelectric constant (d 33 =180 pC/N) and electromechanical coupling factor (k p =0.28), accompanied by a large remanent polarization of P r =37.1 μC/cm 2 and a low coercive field of E c =42.7 kV/cm.