Abstract: One yāna thought consists of two aspects:distinction and introjection."Distinction" is to analyze and judge their differences and excellence and defect between Mahāyāna and Hinayāna,as well as among sravakayāna,pratyekayāna and boddhisattvayāna;"Introjection" is to subsume all yānas through the"one-yāna" or the "buddha-yāna",so as to lead all sentient beings to enter the path of Buddha and eventually obtain complete NiravāNa.The one yāna thought was influenced by the Ten-Sthāna-VaibhaSaka Zāstra and nirvānā sutra and the like,and is very much different from the later Huayan thought of "one yāna of different teaching".This unique one yāna thought is of certain significance for the understanding of the evolution of the one yāna thought in Chinese Buddhism.