The present invention provides a nucleic acid conjugate comprising: a double-stranded nucleic acid consisting of a sense strand and an antisense strand and comprising a duplex region of at least 11 base pairs; and a ligand part, wherein an oligonucleotide with a strand length of 17 to 30 nucleotides in the antisense strand is complementary to a target ²2GPI mRNA sequence, and the 3' end or 5' end of the sense strand has a ligand part represented by following formula (I), formula (II), formula (III), formula (IV) or formula (V).