The functional polysaccharides from brown seaweed were isolated by ionexchanger column, and determine the monosaccharide composition by highperformance anion-exchange chromatography (HPAEC). Then, the effects of functional polysaccharides from brown seaweed will be analyzed on cell viability, antioxidation system in primary rat hepatocytes and hepatic protection against carbon tetrachloride (CCl4)-induced hepatic damage. The brown seaweed would be extracted by 3 different solvents in order to get crude polyphenolic substances. And we will use these crude polyphenolic substances treat with β cell for analyzing cell viability and insulin secretion.