This work is to explore two typical algae as potential cosmetic ingredients. Polysaccharide, algae ooze, and algae powder were extracted from Porphyra yezoensis and Sargassum horneri by water extraction and alcohol precipitation. The content of major components in extracts was analyzed, and the effects of moisture retention and absorption, anti-oxidation, and anti-radiation evaluated. The results showed that algae powder was generally superior to algae ooze in moisture retention and absorption, in which S. horneri powder had the maximum moisture retention after 30 min (95%), while the powders of P. yezoensis had the highest moisture absorptions, up to 93% of that in glycerinum. Moreover, polysaccharide extracted from S. horneri was superior to that from P. yezoensis in moisture retention, anti-oxidation, and anti-ultraviolet. All the results provide reference for the development of algae derivatives, on e.g., cosmetics.