The fossil plants in this paper were collected from the Sunan Formation of Late Permian in Yumen of Gansu Province， China. The flora is composed of 26 species in 16 genera and it contains many Angaran elements and some Cathaysian elements， which represents a mixed Cathaysian—Angaran flora. On the basis of the floral composition， the geological age of the flora belonged to the early Late Permian， corresponding approximately to Wuchiapingian. The flora provides new evidences for the relationship between the Cathaysian flora and the Angaran flora and it has important palaeophytogeographic significances.