The present invention provides a non-overlapped-extension-implantation (NOI) nonvolatile memory device capable of being treated with anti-fuse operation. Differing from conventional anti-fuse memory devices, the structure and fabrication of this NOI nonvolatile memory device are complied with currently-used standard COMS processes; that is, the NOI nonvolatile memory device provided by the present invention can be manufactured through the standard COMS processes, without using any additional masks for defining specific oxide layer. The most important is that, after the NOI nonvolatile memory device is treated with the anti-fuse operation, the Gate and Drain of the NOI nonvolatile memory device still propose the switching characteristic the same to the traditional MOSFET, resulting from the oxide breakdown caused by a high electric filed merely occur in an overlapped oxide segment of the gate oxide layer.