Japanese Buddhism was introduced from Korean Peninsula and China at the beginning, so the history of Japanese Buddhism can also be represented as a history of Cultural Interactions. One of the most significant examples is the establishment of Tendai school in the ninth century. Tendai school became one the most powerful schools in Japanese Buddhist history, and highly influenced the development of Japanese Buddhism. Tendai was named after the Tiantai school in China, and it revealed their tight connections within the East Asian Buddhism. My dissertation takes sangha, ritual, and power as different perspectives to inspect Tiantai/Tendai Buddhism, in order to consider the characteristics of Tiantai/Tendai Buddhism within East Asian cultural interactions. First, take sangha for example, Tiantai community were active around Taizhou, where Temple Guoqing located, Mingzhou area, and Temple Yuquan in Jingzhou. In Tang dynasty, Tiantai Buddhism had no clear connection with capital city or central government and kept its locality. At the same time, Tiantai Buddhism was highly international for its location. Tiantai texts have been introduced to Korea and Japan, and sometimes imported back to China as well. That is, this kind of interaction has made Tiantai Buddhism important resources in East Asian cultural interactions. Buddhist culture as resources can be related to different meanings, and ritual is one of them. Sangha defines their own rituals, and rituals reflect values they share. Inspecting ritual texts of Tiantai/Tendai Buddhism can help us understand how they regard the ruling class headed by emperor. With the transmission of Tiantai/Tendai Buddhism, rituals as part of the discourse resources were also comprehended. Thereafter, how would Japanese Tendai school utilize these ritual resourc
