It is intended to provide an agent for treating or preventing hyperuricemia, gout, inflammatory bowel disease, diabetic nephropathy, diabetic retinopathy and so on which has a non-nucleic acid structure and exerts an excellent xanthine oxidase inhibiting action and a hypouricemic effect. It has been confirmed that a novel triarylcarboxylic acid derivative, which is characterized by having a carboxyl-substituted heteroaryl group and an aromatic ring group such as a phenyl group attached in para-position on a benzene ring and further carrying a cyano group on the same benzene ring, has a potent xanthine oxidase inhibiting action and a hypouricemic effect. Thus, it is found out that this compound is appropriately usable as an agent for treating or preventing hyperuricemia, gout, inflammatory bowel disease, diabetic nephropathy, diabetic retinopathy and so on.