Abstract: Through core observation and by virtue of technical methods such as slice appraisal,physical property analysis and scanning electron microscope observation,the lithology characteristics,the diagenesis,the pore structure,the phys- ical properties and influential factors of Quantou Formation in the north of Honggang area,Jilin province,are studied. Results indicate that the reservoir lithology of lithologic pool in Quantou Formation is mainly feldspar lithic sandstone in the north of Honggang area,with components and structure of low maturity.Due to strong diagenesis,the sandstones in the reservoir have undergone compaction,cementation and dissolution,which is the stage-B of late diagenesis.Reser- voir spaces are mainly the intergranular pores and the sec- ondary solution pores.The physical properties were doubly affected by diagenesis and sedimentary microfacies,so the porosity and the permeability are low.The vertical compac- tion and cementation made these physical properties obvious- ly low,but the dissolution generated secondary pores that improve the physical properties.And the lateralphysical properties of reservoir are subject to the sedimentary facies. Integrative analysis shows that the subaqueous distributary channel and the abandoned channel micro-facies were favor- able facies belt for hydrocarbon accumulation,hence the tar- gets of exploration.