Abstract: Organic-rich shale samples were collected from the Upper Ordovician Wufeng-Longmaxi formations in the Jiaoshiba structure in the Sichuan Basin to carry out rock, kerogen and micro-fossil analyses. The biological recognition and organic petrologic analysis of hydrocarbon generation were carried out, and the hydrocarbon potential was discussed. Hydrocarbon precursor organisms in the high-maturity or over-mature Wufeng-Longmaxi shale mainly included acritarchs, alginite (lamalginite and benthic algae) and zooclasts (graptolite, chitinozoan and spicule), which were the major components of formed organic matter. However, amorphous organic matter was the primary portion in the Wufeng-Longmaxi shale, and was dispersed in the mineral matrix as fined particles. Shale gas in Jiaoshiba area was derived from hydrogen-rich alginite and macromolecular lipid polymer in graptolite tracheids. Abundant amorphous organic matter, especially plenty of pore-filling fine-grained bitumen, indicated that the source rocks have high hydrocarbon potential, which could form large shale gas fields.