Cold sintering process (CSP) has attracted much attention because of sintering various ceramics in the low temperature. In particular, barium titanate (BaTiO3) has been used for multi-layer ceramic capacitors. In the conventional sintering, BaTiO3 is sintered at temperature more than 1000 ˚C. Therefore, we investigated about preparation process of BaTiO3 sintered body by CSP. As a procedure, after mixing homogenously BaTiO3 powder with flux, we densify the powder below 300 ˚C, under uniaxial pressure of 350 MPa with a transient phase. As a result, we obtained the sintered body of the relative density more than 90 %. In this study we will consider the microstructural -processing- property relations for the cold sintered BaTiO3, we are particularly interested in the crystal structure of the ferroelectric phase, and electrical properties as a function of temperature and applied field within pure BaTiO3 and in composite forms with mixing polymer in the grain boundaries.