Abstract: As a kind of unconventional natural gas,shale gas owns the characteristics of self-generation,self-preservation,low-porosity and low-permeability.The accumulation mechanism of shale gas is similar to conventional gas,and free gas makes the largest contribution to the production.High yield shale gas reservoir needs to have the following four basic conditions:(1)Shale layers with continuous and powerful hydrocarbon generation ability;(2)Highly developed mesh micro fractures;(3)A closed gentle anticline which is benefit for gas preservation;(4)A lithological trap,in order to reduce gas from escaping.The tectonic movement effect is less and all key elements of shale gas accumulation satisfied the area,especially the black shale of lower Silurian Longmaxi formation and lower Cambrian Niutitang formation in Sichuan basin is the main research object and should be regarded as the key target of exploration.