A method for forming an antifuse on a substrate is provided, which comprises: forming a first conductive material on the substrate; placing the first conductive material in an electrolytic solution; performing anodic oxidation on the first conductive material to form a nanowire made of the first conductive material and surrounded by a first dielectric material formed during the anodic oxidation and to form the antifuse on the nanowire; and forming a second conductive material on the antifuse to sandwich the antifuse between the first conductive material and the second conductive material.