Freshwater fish fauna of the Kurose river system, the Nuta river system, the Seno river system and the Ohta river system running through the Saijo Basin (Higashihiroshima City, Hiroshima Prefecture) and its surrounding areas was surveyed. As the result, 13 families including 25 species of freshwater fishes were recognized. Among them, Carassius auratus langsdorfii, Nipponocypris temminckii and Zacco platypus showed wide distribution in this area. Liobagrus reini distributed in the restricted areas. Six species, Carassius cuvieri, Channa argus, Lepomis macrochirus, Micropterus salmoides, Oncorhynchus masou ishikawae and Poecilia reticulata, were obvous alien species. Lethenteron reissneri (Petromyzontidae, Agnata) was found at Nuta river of Kami-takeni, Fukutomi-cho which was the neighboring area of Zoga river.