Brown seaweed is distributed around the sea coast in Taiwan, Korea, Japan, China…etc. Besides of using as vegetable, brown seaweed is a kind of traditional medicine prepared by boiling the seaweed in water. In order to explore the effect of brown seaweed, we used the water extract of Sargassum hemiphyllum, Undaria pinnatifida and Laminaria Japonica to do the anti-oxidative and immune activity analysis. It was found that the water extract of S. hemiphyllum, U. pinnatifida and L. Japonica contained high concentration of polysaccharide and sulfate. And S. hemiphyllum was the highest one among them and the molecular weight of polysaccharide was major composed of low molecular weight (<504 Da). The efficiency of anti-oxidative and immune activity was: S. hemiphyllum＞L. Japonica＞U. pinnatifida. Thus, the water extract of S. hemiphyllum was used for anti-inflammation analysis in vitro and in vivo. In cell culture assay, it was demonstrated that water extract of S. hemiphyllum regulated NF-κB transcription factor, and then inhibit the mRNA expression of pro-inflammatory gene, cytokines and inflammatory product secretion. In animal model, it was also proved that no matter in gavage or painting model, the water extract of S. hemiphyllum inhibited ear swelling, erythema and infiltration in mice. Dosidicus gigas integument lipidic extract was a ω-3 enriched phospholipid, which successfully protected SH-SY5Y cells against the cytotoxicity, markedly increased the cell proliferation, antioxidant enzymes of glutathione contents and catalase activities, and inhibited the secretion of amyloid β-peptide 1-42.