A method and composition for preventing and treating Avian Influenza utilizes an effective quantity of polyphenolic(s) and its derivatives in combination with a carrier. The anti-avian influenza ingredient having a composition selected from the group consisting of theaflavin, theaflavin-3,3'-digallate, theaflavin-3-monogallate, theaflavin-3 gallate, theaflavin-3'-gallate, thearubigin, gallic acid, tannic acid, (-)-epigallocatechin gallate (EGCG), (-)epigalloatechin (EGC), (+)-epicatechin (EC), (-)-gallocatechin gallate (GCG), and catechin.