Fairly wellpreserved pygidiums and cephalon of phychopariids were discoveried for the first time from the middle—upper part of Member 2, Nanhao Formation, in Jinbolaocun Village, northwest of Hainan Island. They include Australosutura sp.，Conophillipsia sp.，Hunanoproetus sp.，Linguaphillisia sp.，Weberiphillipsia cf.linguiformis Yuan & Li, and W. sp., and widely spread in Lower Carboniferous. The discovery of these trilobites offer some new information on the geological distribution of Lower Carboniferous trilobites in the world. In addition, it also provides the precise trilobitebiostratigraphic data for the revision of chronologic age of the Nanhao Formation, and the stratigraphic correlation of the Nanhao Formation both on the island and adjacent continent areas. Meanwhile this fauna is very similar to the Tournasian trilobites occurred in Rangari Limestone, the member of Tulcumba Sandstone New South Wales, Australia. They may belong to the same palaeobiogeographic province.