Abstract: A new galeaspid, Zhaotonggaspis janvieri (gen. et sp. nov.), from the Posongchong Formation (Early Devonian Pragian) of Zhaotong northeastern Yunnan, China is described. This genus is characterized by at least 31 pairs of branchial fossae, which is the highest number ever recorded in agnathans. Its overall morphology is suggestive of both the Polybranchiaspiformes and Huananaspiformes. A new galeaspid family, Zhaotongaspidae (fame nov.), is erected on the basis of the Zhaotong material, and suggested that Antiquisagittaspis is a possible member of the new family. It is also proposed that the Zhaotongaspidae might. have the close affinity with the Duyunaspidae.