Abstract: Two forms of Muridae, Progonomys sinensis sp. nov. and Muridae gen. et sp. indet. from the late Miocene Bahe Formation at Lantian, Shaanxi Province are described. The new species, occurring in lower horizons of the formation , demonstrates intermediate characters between P. cathalai and P. woelferi in dimension and morphology. The new murid argues for an age of early late Miocene for the lower portions of the Bahe Formation , corresponding to early Baodean of Chinese Land Mammal Age, which can be correlated with late Vallesian or MN10 of Europe. Consequently, the new species is important because it repre2 sents diversity in the species of the genus Progonomys and the oldest murid known in China. The indeterminate species was probably closely allied to the new species.