The present invention relates to a novel and useful galactose derivative constituting a drug carrier by which a medicine can be efficiently transferred into the liver, a drug carrier comprising the derivative, and a pharmaceutical composition comprising the carrier and a medicine. The present invention also relates to a galactose derivative made up of galactose, a suitable spacer and a certain lipid, a drug carrier comprising the derivative and a cationic lipid, and a pharmaceutical composition comprising the carrier and a medicine (preferably a double-stranded RNA, a double-stranded DNA, or an oligo nucleic acid).