An object of the present invention is to provide a liposomewhich is excellent in intrapulmonary delivery controllability of drugsor genes and is suited for pulmonary administration.By modifying the surface of a liposome using a terminalhydrophobized polyvinyl alcohol and/or chitosan, retention of drugsor genes encapsulated in the liposome on the surface of lung tissueand transfer of drugs or genes into lung tissue can be properlymodulated, and thus in vivo behavior can be controlled.