Provided is an
oligonucleotide capable of inducing the editing activity of ADAR in a
cell and having excellent stability. The
oligonucleotide comprises a first
oligonucleotide and a second oligonucleotide linked to the 5'-side of the first oligonucleotide, and is capable of inducing the site-specific editing of target
RNA. The first oligonucleotide includes: a target-corresponding
nucleotide residue; an oligonucleotide that is located on the 5'-side of the target-corresponding
nucleotide residue, is complementary to the target
RNA, and is composed of 3 to 6 residues; and an oligonucleotide that is located on the 3'-side of the target-corresponding
nucleotide residue, is complementary to the target
RNA, and is composed of 10 to 24 residues. At least one of a
phosphorus-containing linking group that links a first
nucleoside residue to a second
nucleoside residue and a
phosphorus-containing linking group that links a fourth
nucleoside residue to a fifth nucleoside residue is an alkylphosphonic acid residue, an
alkyl phosphate residue or a substituted
phosphoramide residue, wherein the nucleoside residues are numbered from the target-corresponding nucleotide in 3' direction. The second oligonucleotide has a nucleotide residue in which a nucleotide residue corresponding to the target RNA is deleted at the 3'-end or does not form a
complementary pair with the target RNA. The second oligonucleotide is composed of 2 to 10 residues, wherein a nucleotide residue other than a nucleotide residue located at the 3'-end is complementary to the target RNA.