Zhiyi absorbs ānāpāna-smṛti (breathing meditation) from Indian Buddhism and reconstructs it to become an important element in his three types of meditation. Firstly, Zhiyi’s Stages of Meditative Perfection (T 46, no. 1916) presents ānāpānasṁṛti as being of Indian origin but is reconstructed to adapt with Zhiyi’s system. Secondly, ānāpāna-smṛti is gradually transformed into Tiantai Buddhism style in his Six Profound Methods (T 46, no. 1917) and Minor Meditation (T 46, no. 1915), which means that it presupposes the Tiantai theory of three contemplations (guan) in one mind and the Chinese concepts of Mind, Nature, Substance and Function. Finally ānāpāna-smṛti is one part of the dhyāna method of Zhiyi’s Mohe zhihguan, but its exposition of ānāpāna-smṛti here is already taken under the principle of perfect and sudden meditation. My article examines this process of transformation of the practice of ānāpāna-smṛti in Zhiyi’s different texts.