Abstract: In order to analyze the characteristics of the lithofacies and sedimentary facies of the Lucaogou Formation, we investigated a number of samples collected from the well drilling ZY3 and from the outcrop in the field.Furthermore, we analyzed the mineral composition, porosimetry and permeability, microstructure of pores and fractures, and mechanical parameters of the rock, and we discussed the factors influencing them.The shale reservoir in the Lucaogou Formation exhibits ultra-low porosity (0.98% in average) and permeability (0.04mD in average).The microporosity is mostly constituted by matrix intergranular pores at μm scale, which confer poor connectivity and adsorption capacity.The main types of reservoir spaces are the cracks and microcracks, where the shale gas can be reserved in dissociated state.The cross-plot of the Poisson's ratio (0.22 in average) and Young's modulus (1.34 × 10⁴MPa in average), as well as the content of brittle minerals (66.98% in average), suggest that the shale reservoir in the Lucaogou Formation has a high degree of brittleness and offers favorable conditions for natural fracture development.The development of the shale reservoir in the Lucaogou Formation is mainly influenced by the sedimentary environment, mineral composition, and diagenesis.