Abstract: The present invention relates to a pharmaceutical composition for the treatment and/or prevention of a neurodegenerative disease, comprising the following polypeptide shown in any of (a) to (c): (a) a polypeptide comprising the amino acid sequence represented by Ser-Ala-Leu-Leu-Arg-Ser-Ile-Pro-Ala-Pro-Ala-Gly-Ala-Ser-Arg-Leu-Leu-Leu-Leu-Thr-Gly-Glu-Ile-Asp-Leu-Pro (SEQ ID NO: 1); (b) a polypeptide comprising an amino acid sequence having a deletion, substitution, insertion, and/or addition of one or several amino acids in the amino acid sequence consisting of Ser-Ala-Leu-Leu-Arg-Ser-Ile-Pro-Ala-Pro-Ala-Gly-Ala-Ser-Arg-Leu-Leu-Leu-Leu-Thr-Gly-Glu-Ile-Asp-Leu-Pro (SEQ ID NO: 1), and having an activity that inhibits neuronal cell death associated with neurodegenerative disease; and (c) a modified polypeptide from the polypeptide (a) or (b), or a pharmaceutically acceptable salt thereof, as an effective ingredient.