For many generations, marine algae have been extensively used as food for humans as it contains high amount of protein, lipid, vitamins, and minerals. These algae also contain various secondary products such as flavonoids, terpenoids, and alkaloids, which are known to have anti-oxidant or anti-microbial activities. Enteromorphacompressa, commonly known as green confertii, is an edible green algae found all throughout the world. It grows abundantly in spring season. In Korea and China, it has been used as a folk medicine as well as a cosmetic ingredient. Scientifically, E. compressahas been reported to show anti-oxidant effect by scavenging free radicals and to show anti-allergic effect by alleviating the IgElevels raised by allergens. It is also reported that it contains tannin and acrylic acid, which are known to have anti-microbial activity. The essential oil of E. compressashowed anti-oxidant activities and the high content of 1,2-benzenedicarboxylic acid in the essential oil may be responsible for this property.