In recent years, Sinopec has used the unconventional natural gas idea to strengthen the Permian natural gas exploration in eastern Sichuan and obtained industrial gas flow in the first member of Maokou Formation of several wells in Jiaoshiba of Fuling and its adjacent area, revealing a good prospect for natural gas exploration. In this paper, the sequence stratigraphy, sedimentary characteristics, hydrocarbon generation conditions, micro pore structure characteristics and gas bearing property of Mao-1 Member in Jiaoshiba area are systematically analyzed. The results show that: ① Mao-1 member can be divided into two fourth-order sedimentary cycles and eight small layers, which mainly develops four kinds of lithology such as Limestone, micritic limestone, nodular limestone and nodular micritic limestone. ② The average TOC of the Mao-1 Member ranges from 0.75 % to 0.87 %, which on the whole, belongs to carbonate source rock with medium organic matter abundance. The organic matter abundance of micritic limestone and nodular micritic limestone is relatively low, while the organic matter abundance of limestone and nodular limestone is relatively high. The type of organic matter is mainly type I and supplemented by type Ⅱ. R_o ranges from 1.71 % to 2.18 %, with an average of 1.97 %. ③ The Mao-1 Member is an ultra-low porosity and permeability reservoir, and the local layers show the characteristics of fractured reservoir. The reservoir space is mainly composed of organic pores, diagenetic contraction fissures of clay minerals, and grain margin fractures of mineral particles, followed by dissolution pores of carbonate minerals. Moreover, the pore size distribution is mainly mesoporous and macroporous. ④ The natural gas of Mao-1 member is mainly composed of methane with low heavy hydrocarbon content, which is typical dry gas; δ ¹³C₁ ranged from -31.25 ‰ to -31.12‰, δ¹³C₂ is between -35.28 ‰ and -31.23 ‰, δ¹³C₃ is between -34.87 ‰ and -34.66 ‰, which is a typical oil type gas. The carbon isotope of alkane series is reversed, showing a trend of change δ¹³C₁>δ¹³C₂>δ¹³C_3. According to the characteristics, the natural gas from Mao-1 Member is the mixture of kerogen cracking gas and liquid hydrocarbon cracking gas. ⑤ Mao-1 Member has the characteristics of self-generated and self-reservoired, which is a set of special carbonate reservoir between shale reservoir and fractured reservoir. It is necessary to learn from shale gas exploration experience, strengthen sweet spot interval evaluation and adaptive engineering technology research, and promote the large scale production and benefit development of natural gas.