Abstract: The legitimacy of Emperor Yongzheng's succession to the imperial throne has been a controversial issue among Qing historians since the early 20thcentury． Those scholars who hold the view that his 14 th brother was originally the designated heir by Emperor Kangxi，but Yongzheng usurped the throne through devious means． One version of the “usurpation theory ” is that Yongzheng had first stolen his 14th brother's name and made it to be his own，while at the same time fabricated a new name———Yun-ti———for his 14th brother in order to cover up the illegitimate nature of his throne． However，their findings are altogether erroneous because they failed to find out the 14 thbrother's name from the Zongshi Yudie ( Genealogy of the Imperial House) ． On the other hand，scholars who hold the view that Yongzheng's throne was indeed legitimate and the change of names among his brothers was simply atraditional practice under the imperial institution． They identified the original name of the 14 th brother from the Zongshi Yudie． This article is intended to be a critical review of the historical sources used by both sides of the scholars．