The present invention provides a cationic lipid represented by formula (I) (in the formula, R1 and R2 are C8-24 alkyl groups or the like, R3 is a hydrogen atom, C1-3 alkyl group, formula (A) (in the formula, R4 and R5 are hydrogen atoms or the like, n3 is an integer of 2-6), or formula (B) (in the formula, R6 and R7 are hydrogen atoms or the like, n4 is an integer of 1-6), n1 is an integer of 0-4, n2 is an integer of 1-4 (however, cases when n1 is 0 and n2 is 1 are excluded)), and compositions and the like containing this cationic lipid and nucleic acid.
