PROBLEM TO BE SOLVED: To find out physiological activity of fucoidan, and provide the same to new applications.SOLUTION: The elastic-fiber formation promotor containing low-molecular fucoidan as an effective component is prepared. Such fucoidan is preferably derived from at least one kind of brown algae selected from the group belonging to orders Ralfsiales, Dictyotales, Clordariales, Scytosiphonales, Cutleriales, Sporochnales, desmarestiales, Laminariales, Ishigeales, Fucales, Ectocarpales, Dictyosiphonales, Syringodermatales, Sphacelariales, Tilopteridales, Ascoseirales and Durvilaeales. Further, a composition for elastic-fiber formation promotion containing such low molecular fucoidan is prepared.
