A new lithostratigraphic unit, the Hesheng Formation, is erected to represent Cisuralian (Lower Permian) terrestrial strata characterized by the Cathaysia flora in the Yanbian area, place w:st="on">JilinProvinceplace>. The type section of the formation is the Heshengcun section in the vicinity of Hesheng Village of Daxinggou Town, place w:st="on">WangqingCountyplace>. The Hesheng and Dasuangou formations constitute a Cisuralian-Guadalupian transgressive sequence on the northern margin of the North China Plate. Biostratigraphic evidence suggests that the Hesheng Formation is of Late Cisuralian (Artinskian-Early Kungurian) in age.