Abstract: The comparative study of reservoir horizons,reservoir types,sedimentary evolution and karstification phases indicates that there are both similarities and differences in reservoir horizons,sedimentary evolution and karstification phases of the Ordovician carbonate reservoir rocks in northern and central Tarim Basin,Xinjiang.In the petroleum exploration in central Tarim Basin,particular attention should be drawn to the Upper Ordovician reef reservoirs due to their differences in the development of palaeo-weathering crust karsts in the Lower Ordovician strata in northern Tarim Basin.