Abstract: Fucosterol, saringosterol and polyccharides were extracted from Sargassum fusiforme. Silica chromatography, extraction and recrystalization were conducted for separation and purification. Element analysis, Mass spectrometry(MS), nuclear magnetic Resonance(NMR) and Infra red(IR) were conducted for further analysis of fucosterol and saringosterol. Several de-protein and decoloring methods of the polysaccharides were also compared to determine the most effective extraction procedure of Sargassum fusiforme polysaccharides. Extraction conditions of fucosterol were optimized by orthorhombic analysis. Among the four extraction factors concerned, including extraction time, temperature，ratio of sample weight to solvent volume, and concentration of alcohol, ratio of sample weight to solvent volume was the most significant factor that affected the extraction rate, followed by the concentration of alcohol. The optimized extraction condition of fucosterol from Sargassum fusiforme was to extract at 60℃ for 4 h, with 90% alcohol and a 1∶20 sample weight/solvent volume ratio. In de-protein methods, effect of enzyme and Sevag is pretty good. In de-decoloring methods, effect of macroreticular resin is pretty good.