The present invention provides a cationic lipid represented by the formula (I)wherein R1 and R2 each represents alkyl having 8 to 24 carbon atoms or the like； R3 represents a hydrogen atom, alkyl having 1 to 3 carbon atoms, the formula (A)wherein R4 and R5 each represents a hydrogen atom or the like, and n3 represents an integer from 2 to 6, or the formula (B)wherein R6 and R7 each represents a hydrogen atom or the like, and n4 represents an integer from 1 to 6； n1 represents an integer from 0 to 4； and n2 represents an integer from 1 to 4, provided that the case where n1 is 0 and n2 is 1 is excluded, and a composition which contains the cationic lipid and a nucleic acid, or the like.
