Shale gas was first discovered in southeast Chongqing, where is also the key place for shale gas exploration. Formation of shale gas reservoir is controlled by shale thickness, organic matters concentration, thermal evolution, porosity and preservation. Southeast Chongqing hosts two major shale units of rich organic matters, Niutitang formation of lower Cambrian and Wufeng-Longmaxi formation of upper Ordovician-lower Silurian, both bearing thick sediments, high organic matters concentration, high thermal evolution, especially in Wufeng-Longmaxi formation with favorable geology for potential economic shale gas, also in upper Proterozoic Doushantou formation, Permian Changxing formation, Longtan formatin (Wujiaping formation), and lower Silurian Shiniulan formation (Songkan formation), where shall be a good exploration target of shale gas. 