Abstract: The sporo-pollen fossils of the Tertiary Xiejiashan Formation in Lixian County of Hunan Province can be devided into two assemblages. The first one widespreads through out the lower section of the Xiejiashan Formation, which partly consists of Ulmipollenites, U. minor, Plicapollis, Subtricolpollenites. The age of the assemblage is of late Paleocene. The second one distributes at the upper section of the Xiejiashan Formation, which is characterized by Tricolpits and Tricolporopollenites (Ulaceae, Fagaceae, Myrtaceae, Betulaceae) and the age is of early Eocene.