Abstract: The purpose of the present invention is to provide a method for producing a peptide that interacts with a lipid bilayer, and a lipid-bilayer-penetrating peptide obtained through the method. Provided is a lipid-bilayer-penetrating peptide constructed from 10 to 100 amino acids, the peptide having an amino acid sequence that penetrates the lipid bilayer at the C-terminal, and having an amino acid sequence with at least six contiguous arginine at the N-terminal. Also provided is a construct for producing a lipid-bilayer-penetrating peptide, the construct including, from the 5? end toward the 3? end, a tag region 1, a region 1 for incorporating a fluorescent protein gene sequence, a fluorescent protein gene region, a region 2 for incorporating a fluorescent protein gene sequence, a random region, and a stop codon region, and the construct being such that the random region has the aforementioned sequences.