法藏、元曉和見登在其解釋《大乘起信論》的相關釋論之中，逐步吸收了唯識學的理論來加強生滅門的說明，這是站在如來藏說的立場來收攝唯識學，闡釋了「一心開二門」的思想架構，從而充實了如來藏說的理論內涵，發揮了中國佛教的心性論的真如隨緣的課題，本文對此一思想進程加以探討。在吉津宜英的起信論研究所提示的理論背景之中，筆者本文的宗旨有三：(1)本文闡釋法藏與元曉對《大乘起信論》之真心論與唯識論的會通的討論之同異。(2)本文闡釋見登對此一論題的後續討論。見登繼續在種種具體問題之上，發揮了元曉對於玄奘所傳的唯識學與《大乘起信論》的真心論的立場的合會，本論文對見登所延續的討論加以論述。(3)本文在上述如來藏說與唯識思想的交涉的思想史的反省中，本文進一步回到如來藏說的發展史之中，闡釋《大乘起信論》的一心開二門是一種對於兩種如來藏三義思想模型的融合，而有其如來藏說的思想史上的特殊意義。

　　　　　In the perspective of the topic of the interweaving between tathaagatagarbha and vij~naaptimaatra, this paper tackles Fa-Tzang's commentary on the theory of "one heart, two doors" in Mahaayaana`sraddhotpaada. Tathaagatagarbhavada exposes the ontological structure of the absolute mind. Vij~naptimaatravada exposes the theory of the appearing of relative world. How can be synchronized these two trends? The theory of "one mind, two doors" in Mahaayaana`sraddhotpaada includes one understanding about the involving of the theory of the appearing of relative world into tathaagatagarbhavada's exposition of the ontological structure of the absolute mind. But this "involving" includes many theoretical difficulties, therefore Fa-Tzang's, Yuan-hsiao's and Jiann-deng's commentaries on Mahaayaana`sraddhotpaada try to solve these difficulties. This paper firstly tackles the above theme in the Fa-Tzang's commentary on the theory of "one heart, two doors" in Mahaayaana`sraddhotpaada and after then illuminates the continuously exposition in Yuan-hsiao's and Jiann-deng's synthesis of the theory of absolute mind in Mahaayaana`sraddhotpaada and Hsuang-tsang's new teaching of vij~naaptimaatravada.