The name of Toujinyu appeared for the first time in the “Penghu Taiwan Chorography” of Jhen Du, the author of the book”. It is located to the north-northwest of Xiyuping and about 1.9 kilometers away from it. The island has a circumference of 364 meters and an area of 0.46 hectares. About 10 small reefs spread around Toujinyu. The island occupies an area of 3.86 hectares during the ebb tide. Six among the 10 reefs are larger. The island is named because it looks like a headscarf (Toujing) worn as a covering for the head in ancient times when people look into the distance toward the north of the sea surface. In his “Taiwan Chorography”, Gung-Chien Kao said “Toujingyu has a shape of headscarf.”Toujing has a higher terrain and the highest point is 49 meters. The island is surrounded by reefs. A reef named “Toujingzai” is located on the north and 6.1 meters high; a reef named “Niaozaidaizai” is located on the south and 2.8 meters high. There are many seemingly connected small reefs on both east and west sides. They have become ideal habitats for terns and migratory birds (such as black-nappen terns and bridled terns) to breed young birds. Lavers are harvested abundantly in winter.