Abstract: The Lower Devonian strata of the Wenshan Distinct in southeastem Yunnan are well exposed and can be subdivided into Posongchong, Pojiao and Bajiaoqing formations in ascending Older. As a typical non-marine stratum，the Posongchong Formation bears abundant fossils of plants, spores and early vertebrates, including antiarchs，sarcopteryglans and galeaspids such Kwangnanaspis subtriangularis (Cao, 1979), Gantarostrataspis gengi, (Wang and Wang, 1992) and Macrothyraspis longicornis (Pan, 1992) . Recently, new galeaspid specimens were collected from the lower part of the Posongchong Formation in Gumu, Wenshan (Fig. 1). They are referred to Wenshanaspis zhichangensis gen. et sp. nov., Sanqiaspis rostrata (Liu, 1975) and M. longicornis (Pan, 1992) respectively. All of these fossils show that the Posongchong Formation is of Pragian in age, like the Xujiachong Formation in Qujing, eastern Yunnan and the Pingyipu Formation in Jiangyou, Sichuan. Gantarostrataspis gengi and Sanqiaspis rostrata exclusively found in these three regions indicate their biogeographic connection.