The thesis will discuss the foundation of the definition of“the Daibei Group (代北集团)of the five dynasties in the late Tang dynasty”in three folds.Fistly,“rising in the way of local division”does not affect the foundation of Daibei Group;secondly,Daibei Group is a multi -national combination in-cluding multi-national components like the Shatuo (沙陀),Hu (胡)troops,Turk,Huihu (回鹘), Tuyuhun(吐谷浑),Xi(奚),Qibi(契絆),Tartar and Han ethnic group etc.;thirdly,there are “mutu-al interaction and mutual benefit in resources”relationship between Daibei Group and emperors of Tang Dynasty,that is to say,the foundation of the group is the process of“mutual interaction and mutual ben-efit in resources”with Tang rulers.