A cationic lipid having the improved kinetics of cell

The present invention provides a nucleic acid delivery vehicle when used as a cationic lipid enables the high expression efficiency of the cell. (1) a compound represented by the formula wherein Xa and Xb are each independently of X1 or X2; s is 1 or 2, R4 is an alkyl group having 1 to 6 carbon atoms, na and nb are each independently 0 or 1, R1a and R1b each independently having 1 to 6 carbon atoms in the alkylene group, R2a and R2b are each independently an alkylene group having 1 to 6 carbon atoms, Ya and Yb are each independently an ester bond, an amide bond, urethane bond, an ether bond or a urea bond and R3a and R3b are each independently a residue of a sterol, fat-soluble vitamins residue having 12 to 22 carbon atoms or an aliphatic hydrocarbon.