Abstract: By means of the core observation and thin section analysis, the dolomite of Cambrian in eastern Tarim basin is dominated by secondary dolomite which is divided into replacement dolomite and cemented dolomite. The development area of the dolomite is the Upper Cambrian Tuershaketage formation and the distribution area is in the east and west tectonic zones of Tarim basin. Geochemical analysis indicates that three dolomitization environments exist including extrasalinity, bury and hydrothermal fluid, and three dolomitization models are revealed including penetration reflux dolomitization, burial dolomitization and hydrothermal fluid dolomitization. The principal control factors for the high quality dolomite reservoir are carbonate sedimentary facies zones and dolomite genetic superimposed models. The seismic facies and the sedimentary facies analyses indicate that the facies of the west of eastern Tarim basin is carbonate platform margin-platform margin slope, the middle is deep-sea basin and the east is middle ramp-external ramp. The thickness of the dolomites in the west carbonate platform margin and the east middle ramp is big. The dolomite with high reservoir quality which is mainly formed by penetration reflux dolomitization superimposed with the burial dolomitization or hydrothermal fluid dolomitization.

Key words: Tarim basin, Cambrian, dolomite, sedimentary faices, reservoir rock