Abstract: Based on experimental technical methods such as thin section identification, elements scanning by X-ray fluorescence (XRF) spectrometer, quantitative evaluation of materials by scanning electron microscopy (QEMSCAN) and imagining by field emission scanning electron microscopy (FE-SEM), the paper investigates the types and combinations of deep marine shale laminae and their effects on reservoir quality in the first submember of Member 1 of Longmaxi Formation (Long 1 Member) in Luzhou block, southern Sichuan Basin. The results show that 8 types of laminae are developed in shale reservoirs, such as authigenic siliceous-organic lamina, carbonate lamina, felsic-carbonate mixed lamina, bioclastic lamina, terrestrial quartz lamina, clay mineral lamina, pyrite lamina, and altered siliceous lamina. In light of the vertical fold relationship, they are divided into four lamina combinations including "authigenic siliceous-organic matter+carbonate+felsic-carbonate", "authigenic siliceous-organic matter+carbonate+bioclastic", "carbonate+clay mineral", and "terrestrial quartz+clay mineral". The felsic-carbonate mixed lamina has relation with the transport and deposition of silty volcanic materials. As being overlayed with authigenic siliceous-organic lamina and carbonate lamina, the lamina combination of "authigenic siliceous-organic matter+carbonate+felsic-carbonate" was formed and developed in the layer 1 of first submember of Long 1 Member, characterized with high total organic carbon content, high content of siliceous and carbonate minerals, developed pores and microcracks, as well as good gas bearing properties. It is the optimal lamina combination. The altered siliceous lamina has relation with the sedimentation of volcanic tuff components, and is locally developed in the lamina combination of "authigenic siliceous-organic matter+carbonate+bioclastic" in the layer 2 of first submember of Long 1 Member, which is the suboptimal lamina combination. The shale reservoirs corresponding to these two lamina combinations is the "sweet spot layer" for the development of shale gas in lower strata of the first submember of Long 1 Member in Luzhou block. Small-scale transgression and volcanic activity led to high local contents of organic matters, authigenic siliceous and carbonate minerals in the layer 6 of first submember of Long 1 Member, thus forming the "carbonate+clay mineral" lamina combination, which is the "sweet spot layer" for the multidimensional development of shale gas in upper strata of the first submember of Long 1 Member.