Abstract: Lianglitage Formation of the Upper Ordovician in the south areas of Tahe Oilfield of the Tarim Basin was consisted of a set of carbonates.By means of study of bore cores and thin sections observation,it indicated that the carbonates of Lianglitage Formation were experienced meteoric vadose zone,mixing-water diagenetic environment,karst,shallow and deep buried diagenetic environment.Study of the fluid inclusions showed that there were three times of oil activity in shallow,deep buried diagenetic period and late diagenetic period.With data of sedimentary facies,slurry leaking,karst,reservoir porosity and permeability,oil and gas output,it was concluded that Lianglitage Formation possessed potential for hydrocarbon exploration and development.