Abstract:Organic-rich shale in western Hunan and Hubei area is characterized by wide distribution, great sedimentary thickness,good hydrocarbon source and high thermal evolution, which has the material basis for shale gas formation. However, preservation conditions are the keys to the accumulation of shale gas. Uplift-erosion intensity, combination of fault and fracture, characteristic of caprock development and fluid sealing property of the shales in the lower Combrian and upper Ordovician-lower Silurian of the lower Paleozoic have been analyzed. The results show that the synclinorium area, where is weakly affected by tectonic activity, has deep buried depth for shale, continuous distribution for cover layer, undeveloped fault-fracture and great sealing property; whereas the anticlinorium area is strongly affected by tectonic activity, and the shale is shallow buried or even exposed to the surface having incomplete cover layer or without it, combining with well developed faults and poor sealing property. Preservation conditions of shale gas were preferable in south of Lichuan synclinorium, north-central segment of Huaguoping synclinorium and middle part of Sangzhi-Shimen synclinorium, where could be considered as favorable target areas for further exploration.