An image retrieval system including: a retrieval subject image storing unit storing images corresponding to first and second characteristic information among semantic characteristic information, physical characteristic information and prominence characteristic information; a retrieval key inputting unit inputting the first and second characteristic information as the retrieval key; a characteristic information converting unit obtaining remaining characteristic information, the physical characteristic information and the prominence characteristic information based on the two semantic characteristics, the physical characteristic and the prominence characteristic information; and an image retrieval unit retrieving an image matching or being approximate to third characteristic information other than the first and second characteristic information among the semantic characteristic, the physical characteristic and the prominence characteristic information, from the retrieval subject image storing unit by the characteristic information converting unit based on the first and second characteristic information, which are inputted by the retrieval key inputting unit.