南北朝正史关于拓跋种姓的表述截然不同:有匈奴、鲜卑两说。“匈奴说”认定,拓跋是匈奴女“托跋”与汉朝降将李陵的后代。代国被前秦攻灭后,苻坚安排独孤、铁弗、贺兰诸部分治其故地,“匈奴说”可能是匈奴系人群主导代北的产物。匈奴族裔对道武帝建国又发挥了重要的作用,“匈奴说”也得以在拓跋内部与“鲜卑说”长期并行。崔浩监修国史,为迎合匈奴系皇后及太武帝本人而重拾“匈奴说”。此说虽因北魏朝臣普遍反对未能写入《国记》,却传至南朝而为《宋书》所采用。中古时期北族种姓的变化,多以政治上的推动为主,并涉及血缘、地域、社会等复杂层面,拓跋种姓“匈奴说”的形成与流传,或许是一则典型的事例。 Northern and Southern Dynasties history of Tuoba caste is completely different: a Hun, Xianbei two said. “Hun said ” finds that Tuoba is the Huns and women “Tuobo ” and the Han Dynasty descendants of Li Ling’s descendants. After the war on behalf of the country by the Former Qin Dynasty, Qiu Jian arranges Tokgo, Tiefu, Helan and other parts of the rule, “Hun said ” may be the product of the dominant generation of people in the Xiongnu. The Xiongnu ethnic group played an important role in the founding of the Taoist Emperor Wu. “The Huns also said that” the Xian Hu said “can be maintained in parallel with the” Xianbei Saying “within the interior of Tuoba. Cui Hao supervision of the history of the state, in order to cater to the Queen of Huns and the Emperor of the Empire and regain the ”Hun said “. Although this theory was generally opposed by courtiers in the Northern Wei Dynasty, it failed to be written in the ”State Record“ and was transmitted to the Southern Song Dynasty for ”Song Dynasty“. In ancient times, the change of caste in Bei ethnic group was dominated by political impetus and involved complicated aspects such as blood relationship, geography and society. The formation and spread of Tuoba caste ”Hun Sue" may be a typical example.