Barium titanate (BaTiO3) has been synthesized using conventional solid state reaction method at sintering temperatures of 1150°C and 1400°C. A single phase tetragonal perovkite BaTiO3 was observed at 1150°C and changed to hexagonal phase at 1400⁰C. The result was confimed by using X-ray diffraction analysis. Hexagonal BaTiO3 exhibits almost linear dielectric constant value between 60 to 120, however the tetragonal phase shows a phase transition from tetragonal to cubic at 120⁰C. The tetragonal phase BaTiO3 has the highest dielectric constant 6000 at Tc and 4000 at room temperature. [ABSTRACT FROM AUTHOR]