Lead-free (Na0.5Bi0.5)(0.88)Ba0.12TiO3 ceramics have been prepared and studied by X-ray diffraction and by the complex dielectric response as a function of temperature, frequency and a.c. field intensity. Relaxor-like dielectric behaviour were induced by barium Ba dopping to Na0.5Bi0.5TiO3. It was shown, that relaxor-like characteristics can be enhanced by the increase of the a.c. field intensity. A sharp increase in the electric permittivity and dielectric loss on heating near 230 degrees C has been observed. This sharp increase in dielectric responses indicates a transformation between classical and relaxor ferroelectric phases. The X-ray diffraction study shows that this transformation corresponds to the first order phase transition from tetragonal to cubic. The use of (Na0.5Bi0.5)(0.88)Ba0.12TiO3 ceramics for device applications has been indicated.