The present invention provides a cationic lipid represented by the formula (I) wherein R 1 and R 2 each represents alkyl having 8 to 24 carbon atoms or the like； R 3 represents a hydrogen atom, alkyl having 1 to 3 carbon atoms, the formula (A) wherein R 4 and R 5 each represents a hydrogen atom or the like, and n 3 represents an integer from 2 to 6, or the formula (B) wherein R 6 and R 7 each represents a hydrogen atom or the like, and n 4 represents an integer from 1 to 6； n 1 represents an integer from 0 to 4； and n 2 represents an integer from 1 to 4, provided that the case where n 1 is 0 and n 2 is 1 is excluded, and a composition which contains the cationic lipid and a nucleic acid, or the like.
