Abstract:A textual research has been conducted to clarify the botanical origin of the herb Youba in ancient medicinal literatures .The name Youba in 《Xin Xiu Ben Cao》 published in the Tang dynasty and 《Ben Cao Gang Mu》 published in the Ming dynasty has been confirmed to be the immature tuber of Pinellia pedatisecta (without branches around the tuber),whereas the same name Youba in 《Zhi Wu Ming Shi Tu Kao》 published in the Qing dynasty refers to Arisaema yunnanense.