The invention provides a virus-inactivating composition with pH of 3.8 to 5.5, containing (A) 0.02 to 0.3 M arginine and (B) a component such as 0.01 to 10 mM flavonoid, polyphenol, or ascorbic acid derivative, 0.005 to 5 mass % of an arginine derivative, and 0.1 to 2.5 mass % of an extract solution of natural product.