The present invention aims to provide an antisense oligonucleic acid with reduced hepatotoxicity. The antisense oligonucleic acid according to the present invention is characterized in that it has a base length of not less than 7 nt and not more than 30 nt, wherein nucleic acid residues of not less than 1 nt and not more than 5 nt respectively from the both terminals are 2′,4′-bridged nucleic acids, 2′,4′-non-bridged nucleic acid residue(s) is(are) present between the above-mentioned both terminals, and one or more bases in the nucleic acid residue(s) of the above-mentioned 2′,4′-non-bridged nucleic acid residue(s) is/are modified.