Abstract: In order to enhance the target interval oil de posit well logging interpretation and the advantageous region forecast precision, using technological means of sandstone thin slice, body of casting thin slice and scanning electron microscope, combined with the log information to study Chang 2 reservoirs four property relations in Bailangcheng area, we thought that the Chang 2 reservoirs is typical mid dle pore low permeable oil layer. The reservoir lithological characteristics are moderate-fine grain arkosic sandstone,the ingredient and the structure maturity is medium. Reservoir space is mainly intergranular hole and corrosion hole;The lithological character, the physical property differencecontrolled the oil reservoir accumulation degree, and has determined the reservoir natural lower limit standard: The porosity is 8%, the penetration coefficient is 0.43×10-3 μm2,the electrical lower limit electronic resistivity is 13 Ω· m,interval transit-time is 231 μs/m.