The lithological characteristics of Ordovician strata in the study area can be distinguished by crossplot of porosity logging series.Based on the data and results of conventional logging, FMI logging, core and microscope, the authors found three kinds of reservoirs on the south slope of Central Uplift Belt:fractured reservoir, vugular reservoir and fractured-vugular reservoir, which present different response characteristics.Ordovician carbonate reservoirs on the south slope of Central Uplift Belt in Tarim Basin can be classified into three types:type Ⅲ, consisting of fractured reservoir and vugular reservoir, is most developed in the study area, type Ⅱ, i.e., fractured-vugular reservoir, takes the second place, type Ⅰ, i.e., cave reservoir, is not typically developed.The authors' understanding is helpful to finding high quality Ordovician carbonate reservoir on the south slope of Central Uplift Belt, Tarim Basin.