The Mahayana-Buddhism is deepest, widest，limitless，boundless.. The ultimate purpose is teaching living beings to be Buddha. Mahayana Buddhism is to let whole being that are all to be Buddha. But as The lotus sutra (《妙法蓮華經》) say :The Buddhas, the World-Honored Ones, appear in the world for one great reason alone that is to teach living beings going to be buddha. The Thus Come Ones have only a single Buddha vehicle which they employ in order to preach the Law to living beings. They do not have any other vehicle a second one or a third one. There is no other vehicle, there is only the one Buddha vehicle. Tathagata-garbha, one of the three lineages of Buddhism, is an important tradition of Mahayana Buddhism. The fundamental doctrine is that all sentient beings have the Buddha nature. The Buddha nature is the proper fruition of all sentient beings. The dependent fruition is developed from the proper fruition. The dependent fruition is the worldly myriad types of dharma. Deliberating on the truthfulness of everything is the Tathagata-garbha. The origin of all phenomena in the world lies within and develops from the Tathagata. It progresses by flowing, transforming, returning, and extinguishing, ultimately back to the Tathagata. The reality of everything is as such-- all are the Tathagata. All Buddhas are awakened to the truth and realize their Buddhahood. All living beings miss the truth and remain living beings. Teaching living beings to accomplish their Buddhahood is the universal value of Tathagata-garbha, which is also the main concept of the Kṣitigarbha Bodhisattva Purrapranidhana Sutra. There are two parts in this thesis. The first part discusses what Tathagata garbha is how it began and developed. It's core thought is derived from the foundations based on sutras and Kastaras. The second part is based on The Kṣitigarbha Bodhisattva Purrapranidhana Sutra to interprete Tathagata-garbha thought, in accordance with the teaching of “The Cachet of One-Veracity” to solidify the value of The Kṣitigarbha Bodhisattva Purrapranidhana Sutrain Buddhism .With these two parts, this thesis is divided into six chapters: Chapter 1. Introduction, discussing the research topic and the problem statement of this thesis. It is divided into three sections: section 1--purpose of this research; section 2--discussing and sorting out of the research document; section 3-- research methods and the scope for this thesis. Chapter 2. “The origin and inheritance of the Tathagata-garbha” will discuss the relationship between it and Chinese Buddhist tradition. Chapter 3. is divided into 2 sections. The first section contains “Introduction”, “Translation,” “Academic Research”, and “Traditional Buddhist opinion about Kṣitigarbha Bodhisattva Purrapranidhana Sutra.” The subject matter begins with Belief、 Vow、 Cultivation, Hearing、Thought、 Discipline, followed by Precept、Samadhi and Wisdom. It explains the Tathagata-garbha thought’s progressing practice steps. Secondly, with the 13 segments of Kṣitigarbha Bodhisattva Purrapranidhana Sutra, we explored the different levels of practices of Tathagata garbha: faith, vow, actions; hearing, contemplation, cultivation, precepts, samadhi and wisdom. These sections serve as the outline to
