College of Earth Sciences, Jilin University, Changchun 130026, China

Utilizing sides identification, scanning electron microscope ( SEM) , inclusion temperature meas2 urement and mercury penetration analysis, the authors study the petrological characteristic of reserviror, diagenesis type, diagenesis stage and model of diagenesis evolution. The rocks of the reserviror in the studied area are fine2 coarse feldspathic lithic sandstone and lithic feldspathic sandstone in type, and the sandstone experienced the diag2 nesis ofmechanical compaction and p ressolution, chemical bond, alternation, corrosion and claymineral inversion. According to the diagenesismarks, the Qingshankou Formation belongs to A2-A3 substages of late diagenesis stage. The model of diagenesis evolution indicates that during the deposit of the Members^2nd-3rd ofNenjiang Formation, the Member1 st of Qingshankou Formation is at the A1 substage of late diagenesis stage, and theMembers^2nd-3rd of Qingshankou Formation are at the B substage of early diagenesis stage and A1 substage of late diagenesis stage; during theMingshui Formation, the whole Qingshankou Formation is at the stage of A2 substage; while in Paleocene, the Member^1st of Qingshankou Formation goes into the A3 substage of the late diagenesis stage, and the middle and upper parts of the Member^2nd-3rd of the Qingshankou Formation are at the A2 substage of late diagenesis stage.