Abstract: Athyrium Roth is a typical Eastern Asiatic genus. There are about 160 species in the world. However, except a few species, most of them occur in the subtropical mountains of eastern Asia, and small part of them occurs in the temperature area of E. Asia. China is the distribution center of the genus with 117 species. The species of Athyrium in Taiwan are particularly close to the species in mainland. Therefore, it is a representative example for revealing the phytogeographical relationship between the two banks of the strait. There are 32 species of Athyrium sensu lato in Taiwan, including 27 species of Athyrium sensu strict, 2 species of Dryoathyrium, 1 species of Lunathyrium, 1 species of Athyriopsis and 1 species of Pseudocystopteris. If ignoring 4 species of Athyrium sensu strict with doubt, there are 28 species in Taiwan at least. Among them, 21 species are in common with mainland, the common percentage is 75%. Moreover, although the other 7 species have not been found in mainland, they are very similar to some species in mainland morphologically. Whether there are the same species, subspecies or sibling species or not? Which is still waiting for the further studies. Among the 16 common species of Athyrium sensu strict between Taiwan and mainland, 7 species are disjunct distribution between Taiwan and Southwest China. Which not only shows Athyrium species in Taiwan have close relationship with mainland species may be with common origin, but also shows the flora of the highland of Taiwan has most close relationship with the flora of the highland in the Southwest mainland. Further investigating and examining of genetic relationship (such as genetic identity) of the common or related species of two banks of the strait with biosystematic or molecular systematic methods, and further understanding and quantitative studies on the historical and geographical relationships between the florae of Taiwan and mainland are necessary.

Key words: biogeography, disjunct distribution, Athyrium, China, Taiwan