An image search program allowing a computer to execute a reference-image retrieving step of retrieving at least one second image selected from first images stored in a storage section, which is similar to a reference image, an image-displaying step of displaying an index image obtained by reducing the second image retrieved, an image-selecting step of causing a person who wants to retrieve images to select at least one third image similar to the reference image, in accordance with the index image displayed, and a symbol-providing step of storing symbols in data regions which are categories provided for the reference image, in association with the third image selected, each symbol representing similarity or dissimilarity.