There are abundant oil sand resources in the Western slope of Songliao Casin, and their formation has a close relationship with the geology, the structure and the oil-gas accumulation in this area. In this paper,we analyzes the lithological and sedimentary characteristics, the porosity and the permeability of the oil sand reservoirs by drilling, taking rock slices, using the materials test data and other information,and it is shown that the oil sand reservoirs in this place can be divided into two types: the high porosity and high permeability reservoirs of underwater distributary channels and the high porosity and medium permeability reservoirs of mouth bars on the delta front. The lithology of the reservoirs is mainly of fine-grained lithic sandstone and the pores of the reservoirs are mainly of the type of intergranuiar pores of primary porosity. Reservoirs have low compositional maturity and medium textual maturity. The main influencing factors of the reservoirs include the sedimentary facies, the diagenesis and the fault, in which the sedimentary facies and the diagenesis play a decisive role and the fault plays a role in some areas.