<jats:p> A decapeptide called sodefrin was isolated from the abdominal gland of the cloaca of the male red-bellied newt, <jats:italic>Cynops pyrrhogaster</jats:italic> . The native peptide, as well as the synthetic one, had a female-attracting activity. Sodefrin was found in the apical portion of the epithelial cells of the abdominal gland. Sodefrin is apparently species specific because it did not attract females of <jats:italic>Cynops ensicauda</jats:italic> . This is the first amphibian pheromone to be identified and the first peptide pheromone identified in a vertebrate.