Integration of graptolite dates obtained from two sections in northern Xinjiang, Northwest China, permits the recognition of one Pridoli biostratigraphic zone, the Monograptus bouceki Biozone. Graptolites described from the biozone comprise Monograptus anerosus Koren, Monograptus mironovi Koren, Monograptus beatus Koren, Monograptus prognatus Koren, Monograptus bouceki Príbyl, Neocolonograptus nimius (Koren), Pseudomonoclimacis bandaletovi Mikhailova, Callograptus flabellatus Boucek, and Dictyonema cf. elongatum Boucek. All are recorded in China for the first time. The fauna, which is indistinguishable from that of the Balkhash area of Kazakhstan, shows strong endemicity, indicating that the two areas formed a single paleobiogeographic unit during the Pridoli.