Five species of the genus Lucifer are found in Japanese waters: L. chacei, L. hanseni, L. intermedius, L. penicillifer and L. typus. The first species is probably a new member to the Japanese fauna. The others have been recorded in many previous reports under the invalid name L. reynaudii. A key to these five species and a distributional map are presented. The shape of the thoracic sternal plate as seen under the scanning electron microscops is proposed as a character that can be used to distinguish between feales of L. intermedius and L. penicillifer.