Abstract: The 3rd and 4th members of Jialingjiang Formation (J3-4) concentrate in the periphery and extended part of the core of Luzhou palaeohigh, while no gas reservoir has been discovered in the core of the palaeohigh. The main cause is that there are no gas generating conditions in the core. At the gas source zone, there are no faults in the gas source zone that are connected with the J3-4 reservoir. Denuded by the Indochina movement, the core of the palaeohigh has no cap rocks like the J4 gyprock. Research shows that the palaeokarst gaps and bores are the basis of J3-4. After evolution for several times, the J3-4 reservoir is combined into the reservoir with complicated palaeostructures, and it is not limited by structures any more. Even though there are palaeokarst gaps and cracks in the syncline, the J3-4 reservoir has broad exploration prospect. Therefore, further exploration will focus on the periphery, the extended parts in the west and east of the core of the palaeohigh.

Key words: Sichuan Basin, Triassic, Jialingjiang Formation, natural gas, exploration, gas reservoir