MaiDiping-QiongZhusi formation in JingYan-QianWei area is an important position in the Sichuan basin for Lower Cambrian shale gas exploration. MaiDiping formation is comprised of the dark gray and gray black phosphorus fine dolomite, the interbed of greyblack black containing silty shale and siliceous phosphorite, siliceous nodules and horizontal bedding. The top of MaiDiping formation is comprised of the interbed of grey and dark grey lithic quartz siltstone and grey silty mudstone. The contact relation between mudstone and siltstone is abrupt. The scour surfaces, convolute beddings, water discharge structures and directional mud particles are typical in gravity flow deposit. QiongZhusi formation is comprised of the unequally thick interbed of black and dark grey shale or silty shale and gray dark gray calcareous fine lithic sandstone, siltstone or argillaceous siltstone, massive and horizontal bedding. There are wavy beddings, small cross beddings, pyrites and fossils of Trilobites and Bradoriids in the top of QiongZhusi formation. Two Trilobites fossil zones are divided: Tsunyidiscus acutus- Tsunyidiscus yanjiazhaiensis and Eoredlichia- Wutingaspis. The Bradoriids fossil zones are divided into three parts: Liangshanella- Tsunyiella, Emeiella-Kunmingella（Validocostatella) fusulus and Kunmingella douville- Chuandianella ovata(Lee)- Mononotella.The research area is located in the west slope zone in the aulacogen which is controlled by xingKai taphrogeny. It is the shelf facies deposits. In this area, there are three sedimentary subfacies including shallow shelf, deep shelf and aulacogen. Additionaly, there are six microfacies which are beach bar, sand and mud of shallow continental shelf, turbidite sand, sand and mud deep shelf, mud deep shelf and bottom of aulacogen belong to the three subfacies. The MaiDiping formation mainly developed deepwater sedimentary structures under the action of the top developed gravity flow deposits, rich in phosphorus, and a small amount of pyrite. In the other part, QiongZhusi formation stable shelf sedimentary tectonic background, with mudstone sediments. phosphorus content is low. And there is a characteristics of the rich pyrite in local in this formation.