Pure and superstoichiometric modified by 2wt.% Bi₂O₃ and 2wt.% manganese oxide (Mn₂O₃) ceramic samples of the binary system 0.71BiFeO₃-0.29BaTiO₃ were fabricated using conventional ceramic technology by double solid-phase synthesis with following sintering. Mechanical activation of synthesized powders was carried out at the stage of manufacturing press powders prepared for sintering. X-ray analysis at room temperature showed that all studied ceramics have pseudo-cubic symmetry. Grain morphology, dielectric and piezoelectric properties of selected solid solutions were investigated. The modification increased the homogeneity of the material, dielectric constant and piezomodulus d33 and also resulted in a decrease in the dielectric loss tangent. The highest piezoelectric coefficient d33=105 pC/N was obtained. Dielectric characteristics of ceramics revealed ferroelectric relaxor behavior and region of diffuse phase transition from the paraelectric to ferroelectric phase in the temperature range of 740–770K.