BaTiO₃ nanoparticles were synthesized by hydrothermal method using amorphous phase TiO₂ precursor as the Ti-source. The microstructure and phase structure were determined using XRD, SEM and Raman spectroscopy analysis results. The results showed that BaTiO₃ nanoparticles have tetragonal structure, average size of about 100 nm was obtained at Ba/Ti ratio of 1.5, synthesis temperature of 200^∘C and reaction time of 12 h. The components of the BaTiO₃ lead-free ceramic system are fabricated by conventional solid-phase reaction from the average size BaTiO₃ particles about 100 nm obtained by hydrothermal process. The effects of sintering behavior on dielectric, ferroelectric and piezoelectric properties of BT high-density ceramic were studied. The BaTiO₃ ceramic composition sintered at 1300^∘C has a relative density of 97%, the value of the electromechanical coefficient kp = 0.40, k33 = 0.42, the large piezoelectric coefficient d33 = 300 pC/N, d31=−125 pC/N.BaTiO₃ nanoparticles were synthesized by hydrothermal method using amorphous phase TiO₂ precursor as the Ti-source. The microstructure and phase structure were determined using XRD, SEM and Raman spectroscopy analysis results. The results showed that BaTiO₃ nanoparticles have tetragonal structure, average size of about 100 nm was obtained at Ba/Ti ratio of 1.5, synthesis temperature of 200^∘C and reaction time of 12 h. The components of the BaTiO₃ lead-free ceramic system are fabricated by conventional solid-phase reaction from the average size BaTiO₃ particles about 100 nm obtained by hydrothermal process. The effects of sintering behavior on dielectric, ferroelectric and piezoelectric properties of BT high-density ceramic were studied. The BaTiO₃ ceramic composition sintered at 1300^∘C has a relative density of 97%, the value of the electromechanical coefficient kp = 0.40, k33 = 0.42, the large piezoelectric coefficient d33 = 300 pC/N, d31=−125 pC/N.