Abstract: Based on a systematic study of previous data and field survey, the authors divided the Linxi Formation into two lithologic members from bottom to top. The first member, mainly distributed in Linxi area, is dominated by gray-purple fluvial sandstone and conglomerate, containing plants of Paracalamites sp., Eichwaldia sp. and Pecopteris sp. The second member, widely spreading in the southern part of Daxinganling region, consists mostly of black gray sandstone-slate with volcanic rocks at the upper part, containing abundant fossils of bivalves and plants such as Palaeanodonta-Palaeomutela assemblage, as well as Paracalamites, Pecopteris, Cladophlebis and Noeggerathiopsis.