The present invention provides a semiconductor structure comprising a wafer and an aligning mark. The wafer has a dicing region which comprises a central region, a middle region surrounds the central region, and a peripheral region surrounds the middle region. The aligning mark is disposed in the dicing region, wherein the alignment mark is a mirror symmetrical pattern. The aligning mark comprises a plurality of second patterns in the middle region and a plurality of third patterns disposed in peripheral region, wherein each third pattern comprises a plurality of lines, and a width of the line is 10 times less than a width of the L-shapes. The present invention further provides a method of forming the same.