Abstract: The technological conditions of functional activities in extracting two kinds of dietary fibers(DF) from Laminaria japonica and Sargassum were studied by ion-exchanging. The results showed that the contents on dry basis of DF and calcium, expansive capacity and water holding capacity of Laminaria japonica were 84.3%, 6.21%, 138ml/g and 6720% respectively, and those of Sargassum were 82.7%, 5.36%, 108ml/g and 5320% respectively for the two kinds of DFs extracted under the optimum activate conditions. The quantity index of two kinds of products were far higher than unactivated DFs. By testing of human body in take orally,two kinds of DFs had a good laxative effect for constipation patient. The effect of Laminaria japonica DF was a little better than Sargassum DF, but the effect of unactivated Sargassum DF was the worst among all.

Key words: Laminaria japonica, Sargassum, dietary fiber, functional activates, physiology function