The saving device for image sharing includes an image acquiring unit configured to acquire the images offered by a sharer of the images, a sharee information storing unit configured to store sharee information with respect to at least one sharee, a subject assessing unit configured to assess whether or not a person subject is included in the acquired images, an image associating unit configured to associate the images assessed as not including a person subject with the images assessed as including a person subject, based on the sharee information, and a shared image determining unit configured to determine the images to be shared with the sharee or sharees from among the associated images and the images assessed as including a person subject, based on the sharee information. The image sharing system and an image sharing method use such a device.