Object of the present invention is to provide a hemagglutinin-binding peptide producing an anti-influenza virus effect higher than that of existing peptides. The present invention provides, for example, a hemagglutinin-binding peptide comprising a polypeptide having any of the following amino acid sequences (i) to (iv):(i) Thr-MeGly-Asp-MePhe-MePhe-Ser-MeSer-His-Tyr-Thr-Val-Pro-Arg (SEQ ID NO:1)(ii) Arg-Val-Ser-MePhe-Thr-Tyr-MePhe-MeSer-Tyr-Thr-Pro-Ser (SEQ ID NO: 2)(iii) an amino acid sequence with deletions, additions, or substitutions of one or several amino acids in SEQ ID NO: 1 or 2 and(iv) an amino acid sequence having 90% or more sequence identity to that of SEQ ID NO: 1 or 2.
