Fuyu oil layer and Yangdachengzi oil layer, developed in the third and fourth members of Quantou Formation, are two of the major reservoirs of Songliao Basin. To study the controls of reservoir physical properties and the causes of low permeability reservoirs of the third and fourth members of Quantou Formation in northern Songliao Basin, the influence factors were studied by using 12 062 data of the measured core porosity and permeability. As the results show, the dominant influence factors on reservoir physical properties are diagenesis, following by sedimentary facies.