Ŭijŏk 義寂 and Sŭngjang 勝莊 both wrote Fanwang jing 梵網経 commentaries quoting the Yogācārabhūmi 瑜伽師地論. However, there is a decisive difference between them in the purpose of such quotations. Ŭijŏk quoted the Yogācārabhūmi in order to expound the Fanwang jing, but Sŭngjang commented on the Yogācārabhūmi itself. These differences are also related to their respective understandings of the precepts戒律. Ŭijŏk held the position that all sentient beings possess buddha-nature一切衆生悉有仏性. For Sŭngjang, the capacity機根 of beings is determined through the five gotra theory五性各別. This is also related to the three categories of pure precepts三聚浄戒. If one holds the five gotra theory, there is a difference in the interpretation of the precepts that are aimed at the improvement of other beings 摂衆生戒. The three categories of pure precepts is an idea not originally contained in the Fanwang jing. However, it was quoted by many commentators after Zhiyi智顗. The five gotra theory is different from the idea of saving all the people that the Fanwang jing emphasizes. In this study, I compare the Fanwang jing commentaries of Ŭijŏk and Sŭngjang, and identify the reasons for those differences and the problems of interpretation.