B.F. BELYSHEV (1973, Strekozy (Odonata) Sibiri, Vol. 1, pts 1 & 2, Nauka, Novosibirsk) noted 25 spp. for PriArgun'ye, that is the western catchment basin of the Argun' (Hailar) River within Chita province of Russia, E Transbaikalia. Additional material, especially that collected by the first author in 1997, increased the list to 32 spp. The absence of any records of Calopteryx and Orthetrum from Transbaikalia is discussed. Coenagrion bifurcation Zhu & Ou-yan, 2000 is synonymized with C. johanssoni (Wallengren, 1894).