The marine park includes the islands of Dongjiyu, Xijiyu, Dongyupingyu, Xiyupingyu, other smaller islets and surrounding waters.

One of the reasons that the national park was established was that it could support a lot of marine life and become a "germplasm bank" of Penghu.

[5][7] The Penghu Columnar Basalt Nature Reserve Nanhai, containing Dongjiyu, Xijiyu and a few smaller islands, was established in 2008.

[7] South Penghu Marine National Park was established on 8 June 2014 and opened on 18 October 2014.

[7] There are also walls built of stone, called "cai zhai", that were used to protect vegetables from strong winds.

[5] Part of the warm Kuroshio Current flows to Penghu, supporting the marine life.