Abstract: A terrestrial stratotype of the Jiufotangian stage has been erected by studying on systematically the Lianggen Village - Donggou Village strato-section, Luanping, northern Hebei. According to standard of a stratotype erected, many courses and methods have been carried out, i.e dividing the section into three lithologic units, erecting conchostracan biostratigraphic six assemblages, chronologically correlating between the Jiufotang-Shahai Formation of western Liaoning and the Jiufotang Formation of northern Hebei, analyzing sedimentologic environments and cycle variations, distinguishing three 3-tier degree sequences of the shallow-lake facies, and re-defining the unit and boundary of Jiufotang Stage. Therefore it's suggested that the Shahai Formation should be incoperated into the Jiufotang Formation, and the unit and boundary strato-types of the Jiufotangian should be set in between Lianggen Village and Donggou Village, nouthwestern Luanping basin, and the occurrence of conchostracan Eosestheria fuxinensis and E. jiufotangensis should be regarded as the indication of the bottom boundary.