The marine algae collected from Lieyu, Kinmen were identified and listed. A total of 64 species of seaweed, belonging to 38 genera and 25 families, and including 16 of Chlorophyta, 16 of Heterokontophyta, and 32 of Rhodophyta. Among them, 18 species are firstly recorded in Lieyu . Most of algae in Lieyu are of temperate elements. Some of algae, such as Grateloupia turuturu, Sargassum thunbergii and Gracilaria chorda. Codium bartlettii appeared in Lieyu, but not appeared in Taiwan . The effects of current on the distribution of algae and the floristic affinity of this island are discussed.