In Paleozoic, it widely deposited a set ofmarine carbonatite and pelite rocks in the northern margin of Upper Yangtze Platform. By means of systematic sampling among 16 sedimentary sections in this area, combined with organic geochemical analysis, it confirms that the effective source rocks mainly developed in Lower Permian, Lower Silurian, Upper Ordovician and Lower Cambrian. The types of the source rocks are Ⅰ and Ⅱ1, which have good capability of hydrocarbon generation, and still have the capacity of gas production. It is concluded that the main source rocks are from Lower Cambrian and Lower Permian，and maybe there are some good source enrichment layers in parts of Lower Silurian and Upper Ordovician.