Carbonate rocks are not only hydrocarbon reservoirs and source rocks but also cap rocks or barrier beds from hydrocarbon in Tarim Basin. Cambrian-Ordovician carbonate rocks develop in platformal and slop facies regions, in which reservoir facies belts are commonly bioclastic bank and sand bank in open platform and platform-marginal slop beak zone as well as dolomite rock flats. Good carbonate source rocks develop in Cambrian-Lower Ordovician and Middle-Upper Ordovician formations. Based on the features of hydrocarbon distribution and accumulation, the author discusses geology characteristics, formation environments of the carbonate rocks, classification of carbonate hydrocarbon reservoirs and the oil and gas exploration prospects and significant aims in the basin.