Nanosized zeolite was prepared in an autoclave at a hydrothermal temperature range of 100 to $170^{circ}C$. In TEM and particle-size analyses, the size of the nanosized powders was found to be 10-300 nm, and its distribution is uniform and spherical, depending on the hydrothermal temperature. XRD confirms that the nanosized powder is MFI zeolite.