PCR-RFLP of Plasmon on 23 species of Roegneria, Elymus, Hystrix and Kengyilia and 1 outgroup (Triticum aestivum L.) was carried out. The segments amplified with 3 cpDNA and 3 mtDNA universal primers were digested by 15 restriction endonucleases. Among 329 bands produced, 304 were polymorphic (92.4%). PCR-RFLP results showed that polymorphisms existed between the four genera and between the species in Roegneria, Elymus, Hystrix and Kengyilia, and genetic similarity coefficient was high. Roegneria grandis, R. aristiglumis, R. elytrigioides, R. alashanica and R. magnicaespes were grouped, while R. caucasica, R. ciliaris, R. amurensis and R. japonensis clustered together. Species of Kengyilia clustered independently. Five species of Elymus, 3 of Hystrix and Roegneria kamoji grouped together. The results suggested Kengyilia was a valid genus. As more cytological and molecular data are available, the taxonomic status of Roegneria, Elymus and Hystrix will be recognized.