Seaweeds have been traditionally consumed as food in East Asian countries, especially in Japan, Korea and China. Recently, they have been generally accepted in part of the dairy diet as a low caloric food in Western countries. Seaweeds contain a large amount of mucilage polysaccharides, such as agar, alginate and carrageenan, which have been utilized as phycocolloids, gelling agents and emulsifiers in the food and pharmaceutical industries. Brown algae have been reported to contain the components of physiological activities. Thus, the demand for seaweeds as foods and biochemical resources is imcreasingly expected. However, limited numbers of seaweed species are available for practical use. Among the remaining unexplored species is Sargassum horneri, a brown alga growing in the coastal sea. S. horneri has been used as food only in some limited areas in Japan, but the food products processed by boiling it have recently appeared in the markets. To enable the practical use of S. horneri as an edible resource, it is important to obtain information about its nutritional components and their seasonal variations in relation to its growth and maturity. In the present review, the author explains about the potential of the Akamoku, S. horneri and food utilization, and discuss mainly that harvested from the Chikuzen Sea, Fukuoka, Japan.