A liposome composition into which a drug can be introduced in a high encapsulation amount, which has sustained release properties to such an extent that an effective concentration can be maintained at a clinically satisfactory level, and which is suitable for subcutaneous administration or the like. The liposome composition includes: a first liposome which has an outer membrane composed of a multilayered lipid bilayer and a plurality of second liposomes which are accommodated in a first liposome inner region defined by the outer membrane and each of which has an outer membrane composed of a lipid bilayer. The lipid bilayer of the second liposomes can be multilayered. The liposome composition has second liposome inner regions each defined by the outer membrane of each of the second liposomes. An ion gradient is formed at least between each of the second liposome inner regions and the outside of the first liposome.
