The present invention relates to a use of seaweed oligosaccharides to prepare a composition for treating or preventing enterovirus 71 (EV71) infection. The seaweed oligosaccharides of the present invention are a combination of oligosaccharides from gelidium and oligosaccharides from monostroma. The composition of the present invention can be used as pharmaceutical composition, food additive or additive for sanitation and hygiene products. Furthermore, the sulfate content of the oligosaccharides from gelidium and the oligosaccharides from monostroma is higher than 10% (w/w), and the oligosaccharide molecular weight of the oligosaccharides from gelidium and the oligosaccharides from monostroma is lower than 5kDa. The composition is capable of increasing the inhibition rate to the EV71 infection.本發明是關於一種海藻寡糖用於製備供治療或預防腸病毒71型感染之組合物的用途。本發明的海藻寡糖是由來自石花菜的寡糖與來自青海菜的寡糖的組合。本發明之組合物可作為醫藥組合物、食品添加物或清潔衛生用品之添加物。