Maxi Slope Area nears Mahu Sag, where second member of Baikouquan Formation has great oil and gas exploration potential. The relative character on reservoir aiming at second member of Baikouquan Formation has not clear recognition, which hinders deeper exploration and needs to search reservoir characteristics and controlling factors of physical property. Through core observation, many rock slices analysis, SEM, physical property and oil testing data, petrology character, physical property, pore structures and reserve spaces in sand-conglomerate reservoirs of different sedimentary environment in second member of Baikouquan Formation are detailed searched, and generalizes controlling factors on physical property of reservoirs for exploiting potentialities. The results showed that rock types in second member of Baikouquan formation in the study area are conglomerate,and the reservoir belongs to ultra-low porosity and low permeability,and there is a positive correlation between the oil-bearing property and the physical property; The reservoir spaces comprise of primary intergranular pores,secondary pores and micro fractures．Sedimentary micro-facies has a large affection on favorable reservoir distribution of favorable reservoir and reservoir quality．Compaction is the basic factor of low reservoir physical property in diagenesis．Cement and sedimentary components provide material basis for later dissolution．The paleogeomorphology control is favorable for the plane distribution of reservoirs,and the abnormal pressure and micro fractures are helpful to the improvement of reservoir physical properties．