The present invention is directed to providing influenza virus infection suppressors which contain a sialylgalactose-binding peptide, for example, a ganglioside GM3-binding peptide, as an active ingredient. Specifically, the invention provides influenza virus infection suppressors which contain the sialylgalactose-binding peptide of the following (a) or (b): (a) a peptide having the amino acid sequence of SEQ ID NO. 1 or 2; (b) a peptide having an amino acid sequence in which one or several nucleotides are deleted, substituted, or added, from/to the amino acid sequence of SEQ ID NO. 1 or 2, and having sialylgalactose-binding activity.