Upper Ordovician Wufeng to Lower Silurian Longmaxi Member-1 marine shale gas reservoir is developed at Jiaoshiba area of Fuling Gas Field, Sichuan Basin. The reservoir shale is of rich pores and crevices as well as fractures that are favorable to gas accumulation. On account of applying the logging evaluation technique, microscopic characteristics of shale reservoir space (porosity and permeability) is qualitatively revealed and some methods of quantitative evaluation of reservoir space are introduced in order to ascertain gas content and deliverability. It is outlined that although the porosity of shale gas reservoir can be counted out by the experienced statistical method, the permeability taken by the logging evaluation technique only reflects a change trend of it in shale reservoir.