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