Abstract: The Late Paleozoic Benxi Formation of Henan Province is a lithological unit containing bauxite and many mineral resources. According to the distribution condition, lithological features as well as paleontological fossils assemblages, the Benxi Formation is divisiable into three normal members, in acceding order they are Huangling Member, Qiaogou Member and Boai Member, among which the former two members are newly named. On the basis of the paleontological fossils assemblages and their correlations of every member, the geological ages of each member are analyzed. According to the distribution and internal and international correlations of the fusulinid and conodont characteristic elements in the first stable limestone layer of the basal part in the overlying Taiyuan Formation above the Benxi Formation, the age of this limestone layer is determined to be the base of Permian System, thus the age of the top limit of Benxi Formation is restrictive beneath the Permian System, so the age of Benxi Formation is ascertainable to be the Upper Carboniferous.