According to the Śrīmālādevī-siṃhanāda Sūtra, the birth and death of all living creatures and the cause of every conditioned existence (生滅法) is not the Tathāgatagarbha, but avidyāvāsabhūmi (entrenchment of ignorance 无明住地). However, the question “Why would the Tathāgatagarbha, which is originally free from evil and defilement, generate mountains, rivers and lands (如来藏本来清净, 為什麼突然生出山河大地)?” is asked in the Śūraṅgama Sūtra, which indicates that the sūtra has a tendency to consider the Tathāgatagarbha as the origin of mountains, rivers and lands. Additionally, in the same sūtra, the Tathāgatagarbha as cittaprakṛti (心性) is qualified with the function of knowing (知). Compared to the theories of Tathāgatagarbha in Indian Buddhism, the theory in the Śūraṅgama Sūtra is apparently of a different nature. Then how did this theory form? Combining the theories of Tathāgatagarbha which were presented by Huiyuan of the Jingying-si and Fazang, this article evaluates the theory of the Tathāgatagarbha in the Śūraṅgama Sūtra on the basis of how these theories of the Tathāgatagarbha were altered.