Provided are: siRNA which is effective for treating fibrosis； and a medicine comprising the siRNA.The siRNA targets a sequence comprising contiguous 17-23 nucleotides selected from the group consisting of nucleotides lying between 1285th nucleotide to 1318th nucleotide, nucleotides lying between 1398th nucleotide to 1418th nucleotide, nucleotides lying between 1434th nucleotide to 1463rd nucleotide, nucleotides lying between 1548th nucleotide to 1579th nucleotide, nucleotides lying between 1608th nucleotide to 1628th nucleotide, nucleotides lying between 1700th nucleotide to 1726th nucleotide, nucleotides lying between 1778th nucleotide to 1798th nucleotide, nucleotides lying between 1806th nucleotide to 1826th nucleotide, and nucleotides lying between 1887th nucleotide to 1907th nucleotide in SEQ ID NO: 1, and has an overall length of 30 nucleotides or less.
