Abstract: Challenging the conventional wisdom that there was no distinction between Di (sons of wives) and Shu(sons of concubines) in the Manchurian imperial patriarchal clan system，this paper analyzes imperial genealogies (Yudie),and demonstrates that there were strict distinctions between Di and Shu.Shu were eligible only when there was no Di or when Di abdicated.This was the same practice used throughout Chinese history.When the right to the throne was confined to Di,there was a change from elder brother to younger brother inheriting the throne，to father to  son during the early Qing.This paper also examines the weakening of the rigid distinction between Di and Shu in the imperial patriarchal clan system.