Provided are: a cationic lipid exhibiting improved intracellular dynamics； a lipid membrane structure including the cationic lipid； and the use thereof. The cationic lipid is represented by formula (1). (In formula (1), R1a and R1b each independently represent a C1-6 alkylene group； Xa and Xb each independently represent a non-cyclic alkyl tertiary amino group having 1-6 carbon atoms and having one tertiary amino group, or a cyclic alkylene tertiary amino group having 2-5 carbon atoms and having 1-2 tertiary amino groups； R2a and R2b each independently represent an alkylene group or oxydialkylene group having 8 or less carbon atoms； Ya and Yb each independently represent an ester bond, an amide bond, a carbamate bond, an ether bond, or an urea bond； Za and Zb each independently represent a divalent group derived from an aromatic compound which has 3-16 carbon atoms, has at least one aromatic ring, and may have a heteroatom； and R3a and R3b each independently represent residue derived from a reaction product of a hydroxyl group-containing fat-soluble vitamin and a succinic or glutaric anhydride, residue derived from a reaction product of a hydroxyl group-containing sterol derivative and a succinic or glutaric anhydride, or a C12-22 aliphatic hydrocarbon group.)
