The present invention provides a small interfering nucleic acid that specifically suppresses HBV gene expression, a pharmaceutical composition containing the small interfering nucleic acid and usable for the prevention and / or treatment of hepatitis B and an siRNA conjugate. . Furthermore, the present invention provides an application of the small interfering nucleic acid to the manufacture of a drug for preventing and / or treating hepatitis B. [Selection] Figure 4本発明は、ＨＢＶ遺伝子発現を特異的に抑制する低分子干渉核酸、該低分子干渉核酸を含有し、Ｂ型肝炎の予防及び／又は治療に利用可能な医薬組成物及びｓｉＲＮＡ結合体を提供する。さらに、該低分子干渉核酸のＢ型肝炎の予防及び／又は治療のための薬物の製造への応用を提供する。【選択図】図４
