This Article based on Sihala Sangha how introduces to South-East Countries in ancient period. The Theravada shape of Buddhism exists in Ceylon, Burma, Siam (Thailand), Cambodia and in Laos. Theravada Buddhism is the tie that binds Ceylon with these kinds of countries of South – East Asia. In approximately the eleventh century A.D. the Buddhist nations in South- East Asia came into near contact with Ceylon, the fountain- head of Theravada Buddhism. From the period onwards Ceylon performed an important function in the established order and development of the Theravada form of Buddhism in one-of-a-kind regions of South – East Asia and the Sinhala Sangha (Ceylon Sangha) constituted a sturdy and vitalizing pressure in the non-secular history of South-East Asia. It's far evident from our sources that everyone the South- East Asian nations Ceylon’s relations with Burma have been the nearest.
This research based on data collection with Primary & secondary Literature Sources. An additive used some special archeological remains and sources for this study.