Abstract: The widely developed Guanyinqiao Member at the top of the Wufeng Formation, Fuling area shows horizontally variable lithology and thickness. There are two main views about the causes of this variability:deep water genesis theory and shallow water genesis theory. This study combined various factors, including sedimentation rate and ecological characteristics, to indicate that the Wufeng Formation was a typical deep water allochthonous deposit. Underflow deposition was the main reason why the underlying Guanyinqiao Member was well developed. Meanwhile, strong underflow sedimentation was the main cause for the lack of Guanyinqiao Member in several areas. Additionally, this work investigated the effect of Guanyinqiao Member on the evaluation of shale gas development from the sedimentary and engineering technological transformation perspectives. The horizontal distribution characteristics of Guanyinqiao Member showed the horizontal differences of three geological elements, including the active degree of underflow deposition, the micro palaeogeomorphology and the distance to source area of gas-bearing shale in the Wufeng-Longmaxi formations, Fuling area. These differences had important effects on the deposition of gas-bearing shale of the Wufeng-Longmaxi formations and the overlying Long2 Member. Therefore, the formation characteristics of Guanyinqiao Member can be used as an important evaluation index for gas-bearing shale strata exploration and development in the Wufeng-Longmaxi formations, South China. Besides, the engineering technological transformation of Guanyinqiao Member is challenging. It is located in the main zone, and should be given full consideration when optimizing the horizontal section of development well.