Tectonicdiagenetic evolution and compaction history of tight sandstone reservoir of Paleogene in the DN2 gas field of Kuqa Depression were studied through core observation, thinsection analysis, scanning electron microscope observation, Xray diffraction, fluid inclusion and reservoir physical parameters analysis, in combination with regional geological research results, such as burial thermal, organic matter revolution and accumulation history. The results show that the sandstone reservoir in the study area underwent a tectonicdiagenetic series and two densification. The tectonicdiagenetic series includes: contemporaneous cementation of carbonate minerals and halitecompaction, cementation and lowmaturity hydrocarbon charging in the early diagentic stageorganic dissolution and liquid hydrocarbon charging in the middle diagenetic stagetectonic compression and fracturing, natural gas charging, and late carbonatic cementation. The mean primary porosity of sandstone reservoir of the DN2 gas field was only 31.7%, with sedimentation being the internal cause of densification. Evolution of the reservoir caused the porosity of the reservoir to the current 58%. Compaction being responsible for 20.8% of loss in porosity is the key factor for initial compaction of the reservoir, and cementation reducing 6.59% porosity intensified the compaction degree of the reservoir. Corrosion and various fracturing increased porosity by 4.28%, which improved the porosity of reservoir up to 11%. The porosity of reservoir during the Kangcun stage (12~5Ma) decreased from 14.5% to 8.0% and completed the first densification process, which is roughly synchronous to densification and the formation of the low anticline structural reservoir. During the past 5 Ma years, the low anticline reservoir underwent strong tectonic compression in Pliocene and reduced the porosity of the reservoir by 2.76%. This is the most important cause of the second compaction process of the reservoir. Migration of large amount of gas generated by Jurassic hydrocarbon source rock formed the current gas reservoir, which is socalled densification coupled with reservoir formation.