The early Paleozoic sedimentary basins in middle-upper Yangtze region were mainly cratonic-marine basin (∈-O2) and the back-bulge basin which developed above the craton basin (O3-S).Due to the constraints of the dominative factors such as the regional tectonics, paleoclimate and the eustatic sea level change and so on, the sedimentary environments in favor of the formation of hydrocarbon source rocks were formed, meanwhile the physical foundation for the generation and reservoir of the petroleum and gas hydrocarbon accumulation was also laid. Early Cambrian, the sedimentary environment of the middle and upper Yangtze region mainly appeared as the neritic environment, the substance Phosphorus brought by the ascending currents and stably distributed black shale were all deposited, the stratum of the Meishucun Formation and Qiongzhusi Formation were the representatives. From Middle-Late Ordovician to Early Silurian, the sedimentary environment of the back-bulge basin was the limited neritic environment, where formed the hydrocarbon source rocks, which were represented by the black shale of the late Ordovician’s Wufeng Formation and the Early Silurian’s Longmaxi Formation. The favorable facies belt of the above-mentioned hydrocarbon source rocks taking on the planar distribution in the middle-upper Yangtze region, were the hydrocarbon-rich depositional areas, and also were the major and first choice areas of carrying out basic geological survey and oil and gas exploration in the Early Paleozoic marine stratum in the Yangtze region.