The article deals with the Islamic religion of Banjar Pahuluan people in the village of Hulu Banyu, sub-district of Loksado, regency of Hulu Sungai Selatan, South Kalimantan Province. Islam as the religion of Banjar Pahuluan people is the local religion deriving from the adaptation toward the surroundings and theological accommodation to the belief of Dayak people. The process resulted in the distinctive characteristic of Islam of the Banjar people living in coastal area. It also triggered the presence of certain systems allowing the establishment of solidarity and social harmony, in term of preserving the myth of badingsanak between prophets Mohammed and Isa, putting the pictures of certain Islamic figures, visiting the cemetery of charismatic Islamic leaders, and conducting religious ceremony. Thus, the systems have shaped the Islamic religion of Banjar Pahuluan people into a mechanism that maintains the good relationship between the people of Banjar and the people of Dayak in Hulu Banyu. Both can live peacefully as badingsanak and as member of the same bubuhan. Keywords: Banjar, Dayak, Islam, pahuluan, function, social harmony