Objective Bioactive components were extracted from Sargassum fusiforme by using different solvents and their activities were detected in vitro in order to screen potential free radical scavenger.Methods Using the assay system of DPPH,superoxide radical,and in comparison with vitamin C,tea polyphenols and a series of extracts of sea tangle,laver.Results Different solvents had different extraction rates,and extracts by different solvents had different free radical scavenging activities.Conclusion 0.5%Na2CO3 solution had the highest extraction rate and extracts by this solution had the best scavenging ability as well.At the same time,the results obtained by DPPH detection method were more stable than those by the others.