The objectives of the research were as follows: 1) to study the Buddhist adaptation of the ethnic community; 2) to study the Buddhist adaptation of the Bru ethnic community, Ban Tha Long, Khong Chiam District, Ubon Ratchathani Province; 3) to analyze the Buddhist adaptation of Bru ethnic community. This study was carried out by means of qualitative research using an in-depth interview with 25 key informants. The obtained data were interpreted by descriptive analysis. The research results were as follows: The Buddhist adaptation of the ethnic community: ethnic community life has brought the Four Saṅgahavatthu Dhamma in Buddhism as a guideline for self-adjustment. Ethnic communities have benefited each other by giving both Dhamma-dāna and Āmisa-dāna. All these Dhammas are linked by activities of multiculturalism. The Buddhist adaptation of the Bru ethnic community in five aspects: concept: attitude adjustment in line with social changes; conduct: adapting to others by creating friendships between ethnic groups; values: learning new things and transferring the way of life of the Bru people to enable learning among other tribes; economics: the Bru people live in areas with natural resources and their careers are more of a self-sustaining economy than technology; cultural traditions: the culture and tradition of the Bru people is the tradition of raising spirits in the house and Heet's spirits combined with Buddhist principles. The analysis of the Buddhist adaptation of the Bru ethnic community: Dāna: helping each other, sharing generosity; Piyavācā: even though they speak different languages, they converse with polite and gentle words; Atthacariyā: they live a life that supports the community by practicing oneself for the benefit of society; Samānattatā: they always behave according to the status of the community and value the equality between the groups.