A seal ring structure is provided. The seal ring structure includes a seal ring on a semiconductor substrate. The seal ring includes a first interconnect element and a plurality of second interconnect elements. The first interconnect element is formed on a shallow trench isolation (STI) region and a first group of P-type doping regions over the semiconductor substrate. The second interconnect elements are formed below the first interconnect element and on a second group of P-type doping regions over the semiconductor substrate. The second interconnect elements are electrically separated from the first interconnect element, and the first and second groups of P-type doping regions are separated by the STI region.