<；P>；PROBLEM TO BE SOLVED: To provide an anti-influenza agent effectively preventing or treating infection of influenza virus, and a composition industrially effectively utilizing the anti-influenza agent. <；P>；SOLUTION: The anti-influenza agent includes an extract of Agaricus blazei mushroom as an active ingredient. The anti-influenza agent is based on such knowledge that insoluble matter obtained by fractional processing of an extract of Agaricus blazei mushroom, more preferably a water extract of Agaricus blazei mushroom, with a hydrous alcohol, exhibits preventive and curative effect against infection of influenza virus. Foods and drinks, medical drugs, feedstuffs and pet foods, all prepared by compounding the anti-influenza agent, are also provided. <；P>；COPYRIGHT: (C)2011,JPO&INPIT
