Abstract: Studies on diagenesis, sedimentary sequence and pore characteristics of carbonate rock under unconformable surface in Tarim basin showed that:①carbonate reservoir under unconformable surface underwent cementation, denudation, dolomitization, recrystallization, compaction, solution, silicification, filling of siliceous cement and fracture, among which cementation, compaction, silicification and filling of siliceous cement were major diagenesis for destroying pores;denudation(especially air water when unconformi ty formed), dolomitization, solution and fracturing were major diagenesis for forming secondary pores.② The pores in carbonate reservoir under unconformable surface during hydrocarbon migrating were all to be secondary, among which intercrystalline pore, intercrystalline denudation pore, cement denudation pore, matrix denudation, vugular pore, denudation fracture and stylolite were main pore types, with pore diameter of 0.01~ 1 mm and vugular pore diameter of 2~ 10 mm, the porosity of 2%~ 8%, larger than 15% in local area.

Key words: Tarim basin, Diagenesis, Pore evolution, Characteristics