An object of the present invention is to provide a drug delivery system capable of sustainedly releasing a drug noninvasively at any given point in time. The present invention relates to a liposome complex comprising a liposome membrane-constituting substance bonded to a light-absorbing compound having an absorption wavelength in the near-infrared region, selected from the group consisting of indocyanine green dyes, phthalocyanine dyes, squarylium dyes, croconium dyes, and diimmonium dyes.