During the solid-phase crystallization of amorphous SrBi2Ta2O9 (SBT) thin films, the grains grew preferentially to the [1 1 0] direction forming elliptical grains. The origin of the [1 1 0]-oriented grain growth is due to the highest ionic packing (0 0 1) SET plane which includes TaO6 octahedra, and the nearest bonding direction of TaO6 octahedra in SBT plane is the [1 1 0] direction. High-resolution transmission electron microscopy acid image computer simulation indicate that antiphase boundary enhances elliptical grain growth between the amorphous matrix and the crystalline SET grain. The formation of a stacking fault results in an antiphase boundary making an atomic step of {0 0 1} planes at the amorphous/crystalline interface. At that interface, a corner of the antiphase boundary acts as preferable nucleation sites by providing an atomic step of {0 0 1} planes and enhances elliptical grain growth in the [1 1 0] direction on {0 0 1} planes.