Abstract: The sporopollen assemblage of Protohaploxypinus-Piceaepollenites Opimus-Alisporites Communis, collected for the first time in the Upper Permian Sizhanbanyan Formation from HFD1 well in northern Songliao Basin, is dominated by the pollen of gymnosperms, while pteridophytes are characterized by low spore content and poor species. Of the pollen contents of gymnosperms, non-striate bisaccate pollen is the highest, followed by striate bisaccate pollen, with less monosaccate pollen, which are comparable with the sporopollen assemblages of the Late Permian in Junggar and Tarim basins in Xinjiang and the Linxi Formation in Daxinganling Mountains, indicating the age is also Late Permian. As the lithologic characteristics of the strata with sporopollen assemblages are similar to those of Linxi Formation, the Linxi Formation of Daxinganling Mountains on the west of Songliao Basin can be introduced to replace the former Sizhanbanyan Formation.