The purpose of the present invention is to provide 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 a effective concentration can be maintained at a clinically satisfactory level, and which is suitable for subcutaneous administration or the like. This 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 multilayered lipid bilayer. 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.
