Abstract: This paper deals with the florule and sporo-pollen assemblage of the Shang-In coal series of Erhyuan, Yunnan. The fossil leaves are mainly of Quercus, Q. semicarpifolia Sm., Q. pannosa H.-M., Q. monimontricha H.-M., Q. gilliana Rehd. et Wils. and Q. spathulata Seem. Besides, there are leaves of Acer paxii Fr., A. sp., Celts bungeana Blume, Viburnum ovalifolium Rehd., and Populus spp., cones of Pinus yunnanensis Fr., seeds of Abies, fruits of Trapa, pollen of Pinus yunnanensis Fr., P. sp., Abies, Picea,Cedrus, Tsuga, Podocarpus, Quercus, Betula, Acer, Ulmus, Michelia, Rosaceae, Erieaceae, Nymphaea, Trapa and Hydrocharis and spores of Polypodiaceae and Pteris. The plant fossils and sporo-pollen assemblage of the Shangin coal series indicate that the palaeoflora is quite close to the modern flora of Erhyuan. The vegetation is a kind of needle and broad-leaved mixed forest inhabiting subtropical mountains. Judging from the stratigraphical sequence and the characteristics of this flora,the geological age of the said coal series is late Pliocene. This flora is also very close to the middle-late Pliocene flora of Mt. Shisha Pangmaand probably belongs to the same palaeoflora. The present investigation leads us togain an insight into the nature of Pliocene flora east to the Himalayas, to determinethe geological age of the coal series, and to provide some palaeobotanical evidence on the history of floristic development of the present flora of western Yunnan.