We sampled the fungi on the grounds of the floor and books in the library for the purpose of attack the fungi in the traditional library. We cultured it on the Sabouraud Dextrose Agar(Baltimore Biological Laboratory) and was obtained the fungi of six species, Here irradiated the ultra violet lamp(100V, 15W, 253Å), which was occurred to the colony after 24 hours. And irradiation by 2hrs/day for 2days here. The other method, we were sterilized test by the methanal fumigation The following results were obtained 1. All rearing is suspensed the result of the ultra violet rays irradiation, but the colony that is gained from the grounds of the floor in the library is not sterilized. 2. The result of air tight box to methanal 14?/㎥ for the 24hours fumigation, each test group(the fungi of six species) is all sterilized.