About 140 scientists coming from 23 countries recently attended an international conference in Nanjing to discuss the latest progress in research into the Ordovician and Silurian Systems. The conference, with the theme "The Global Ordovician and Silurian", combined the 10th International Symposium on the Ordovician System, the 3rd International Symposium on the Silurian System and the 4th Annual Meeting of the IGCP 503 project on "Ordovician Palaeogeography and Palaeoclimate". These combined meetings, convened by Chen Xu (Nanjing, China), Rong Jiayu (Nanjing, China)and Thomas Servais (Lille, France), were sponsored by the Chinese Academy of Science, the National Natural Science Foundation of China and the Jiangsu Association for Science and Technology, and hosted by the Nanjing Institute of Geology and Palaeontology and State Key Laboratory of Palaeobiology and Stratigraphy, NIGPAS.