PROBLEM TO BE SOLVED : To provide targeted lipids advantageous for in vivo delivery of nucleic acid, and to provide lipid particles including these lipids, and nucleic acid-lipid particle compositions suitable for in vivo therapeutic use. SOLUTION : Provided is a targeted lipid of which structure is L100-linker L100 (where L100 is a lipid, lipophilic substance, alkyl, alkenyl or alkynyl, L101 is a ligand or -CH2CH2(OCH2CH2)pO(CH2)qCH2-ligand, p is 1-1000, and q is 1-20.) Further, the invention provides compositions and methods to deliver a therapeutic agent to cells. In particular, the invention provides novel lipid and nucleic acid-lipid particles that enable effective inclusion of a nucleic acid for effective in vivo delivery of the included nucleic acid to the cells. SELECTED DRAWING : None COPYRIGHT : (C)2019, JPO&INPIT