Provided are a siRNA for inhibiting the expression of hepatitis B virus gene, and a pharmaceutical composition and conjugate containing the siRNA. Each nucleotide in the siRNA is independently a modified nucleotide. The siRNA comprises a sense strand and an antisense strand. The sense strand of the siRNA comprises a nucleotide sequence 1 having the same length and no more than three nucleotides different from the nucleotide sequence shown in SEQ ID NO: 155, and the antisense strand of the siRNA comprises a nucleotide sequence 2 having the same length and no more than three nucleotides different from the nucleotide sequence shown in SEQ ID NO: 156.
