|| Barium titanate (BaTiO3) is an important ferroelectric material which has attracted a lot of attention due to its electrical and mechanical properties. Multi-layer ceramic capacitor (MLCC) is a representative field of BT application and size of BT powder is required to decrease with miniaturization. However, size effect of BT, in which pseudocubic phase is stabilized resulting in low dielectric constant, have been limiting the miniaturization. That is, high tetragonality of BT particle is essential to enhance the efficiency of MLCC. In this study, BT nanowire with high tetragonality was synthesized by hydrothermal method with additional ethylene glycol. Influences of the amount of the additive on aspect ratio and morphology have been investigated. Relation of tetragonality and lattice defect has also been examined. We analyzed the mechanism of high tetragonality by XRD, TGA, FT-IR, Raman spectroscopy. This study can lead to the potential of high volumetric efficiency of BT based ferroelectric application.