1863年，先天道張東初傳道越南，並以明師道為名，廣為傳播，影響了越南的民間教派。本文乃探討張東初自立稱祖的自我論述，並以廿世紀明師道德濟宗發展的關鍵人物為主。張東初是先天道第一位落實海外傳教者，並在東南亞廣設道場，他以此論述接續先天道祖師之位的正當性。廿世紀明師道德濟宗的發展，初期以張東初的後輩張道新在越南中部發展優異，張氏的弟子程道清成功地在北部發展，開辦以女性修行團體為主的明師道佛堂。阮覺原是明師道成功在地化的關鍵人物，以他為核心的德濟佛堂系統多以越南人為主，奠定了明師道在南部的厚實基礎。王道深是先天道東初派的第九代祖師，長期經營越南，他以越文撰述明師道的皈依證明，申辦「南宗佛堂居士教會」，對明師道產生重大影響。

In 1863, Chang Dongchu preached Xiantiandao (the Great Way of Former Heaven) religion in Vietnam, naming it Minh S Đ o. His teachings successfully spread and influenced Vietnamese folk religion. This paper aims to explore Chang Dongchu’s discourse about being the founder of the Xiantiandao, and how his followers developed the Tông Đ c T doctrines of Minh S Đ o in the twentieth century. Chang Dongchu was the Xiantiandao’s first proselytizer in Southeast Asian countries, utilizing his success in transmitting this religion’s doctrine and practice as evidence of his legitimacy as a Xiantiandao founder. His follower, Chang Daosin, further developed this religion in Central Vietnam. By founding halls for women believers, Chang’s disciple Cheng Daoqing successfully developed the Xiantiandao in Northern Vietnam. Nguy n Giác Nguyên was critical to the Minh S Đ o’s localization, building the Đ c T Temple (also known as the Nam Nha Temple) and laying a solid foundation for the Minh S Đ o in Southern Vietnam. Wang Daoshen was the nineteenth-generation patriarch of the Dongchu branch of the Xiantiandao, and made a huge impact on the Minh S Đ o’s development. He lived in Vietnam for a long time, prepared a Minh S Đ o certificate of conversion in Vietnamese, and applied to the government to establish the “Lay Buddhist Association of the Nanzong Sect.”