Guan Ding, Zhi Yi's aide and successor, plays an important role in the development of Tiantai Sect. Tiantai Sect is established by Zhi Yi and Guan Ding helps to reach its maturity: first, be collects and edits what Zhi Yi has preached and makes it classic of Tiantai Sect; second, he writes a biography for Zhi Yi's works, and Tiantai Sects thus has its own founder; lastly, he mixes “Study of Tiantai”, unfamiliar to people at that time, and prevailing “Buddhism”, which makes many followers of “Buddhism” converted to Tiantai Sect and Tiantai Sect thus owns its organization, which shows Guan Ding’s bringing new ideas in the Buddhism and his surpassing. Tiantai Sect consequently turns into a forceful Buddhism organization with many followers and its own theoretical system.