The Four Truths as Immeasurable （wuliang sidi 無量四諦） and The Four Unconstructed Noble Truths （wuzuo sidi 無作四諦） have been developed from the Śrīmālā-sūtra （Shengman jing 勝鬘経） and Nirvāṇa-Sūtra （Niepan jing 涅槃経）, which are based on the thought of the store of the Tathāgata （rulaizang 如来蔵）. However, these two kinds of Four Truths assume different meanings according to the contexts between Tathāgata and the Buddha nature （foxing 仏性）. In this paper, I will clarify what Zhiyi （智顗） wants to represent in these two kinds of the Four Noble Truths by examining the Doctrine of the Four Teachings （Sijiao yi 四教義, T. 1929）.
