PROBLEM TO BE SOLVED: To obtain an anti-influenza virus agent which has high safety, is convenient and inexpensive, and contains as an active ingredient the extract of a rosaceous plant that has widely been used for foods, perfumes, miscellane ous goods, and the like, gives a high grade sense, and is one of familiar plants. SOLUTION: This anti-influenza virus agent contains the extract of the rosaceous plant as an active ingredient.
