The present invention provides radioprotective materials and products produced using the materials, the materials and products being easily usable for blocking effects of radiations, exposure to which occurs unconsciously in daily life or in a working environment. Specifically stated, the present invention provides radioprotective materials containing polyamino acid(s) or derivative(s) thereof; the radioprotective materials in which the polyamino acid(s) comprises at least one amino acid selected from the group consisting of glutamic acid, phenylalanine, alanine and leucine; and the radioprotective materials in which the polyamino acid(s) or derivative(s) thereof is modified with sugar component(s). The present invention further provides radioprotective products produced using the radioprotective materials.