There exist complicated mixtures of sandstone and shale in the fifth member of Xujiahe Formation. And it has the low porosity and permeability of the reservoir. Based on sampling of the Lower sandstone and shale, MTS petrophysics test system, ordinary thin and casting thin, it analyzed the characteristics of the sandstone and shale. The test indicates that the stress-strain relation is different between sandstone and shale, the rock trends to display to elastic-plastic deformation; the compressive strength has the positive proportion with confinement pressure and elastic modulus; the shale trends to plastic deformation, whereas the sandstone trends to rigid deformation. Based on the thin and logging interpretation, it matches the formula of dynamicSYoung"s modulus and Poisson"s ratio; calculates the compressive strength from density, elastic impedance andSshale contents; matches the tensile strength with compressive strength; calculates shearing strength with empirical formula;and finally builds up the rock mechanics logging interpretation sections of the fifth member of Xujiahe Formation. The research provides reference to subsequent engineering research, such as fracture analysis and fracturing treatment.