This research, conducted among the Catholic Muyu tribe community at St. Carolus Manggisuba Station, Kuper Parish of the Sacred Heart of Mary, aims to understand and compare the essential properties of marriage according to the teachings of the Catholic Church and the cultural perspective of the Muyu tribe. Sacramental marriage in the Catholic Church is monogamous, indissoluble, and open to life. As a sacrament, marriage is a symbolic act that manifests God's love for humanity. Meanwhile, according to Muyu custom, marriage is an expression of social and kinship ties between extended families through the display of various symbolic elements. This study employs a descriptive qualitative method with a comparative approach. Data were obtained from informants, including traditional leaders, parishioners, the parish priest, and Catholic Muyu couples, through interviews, observation, and literature studies related to Catholic teaching and Muyu custom (surveys and previous research). The findings reveal both common ground and fundamental differences between the two. Common ground lies in the appreciation of fidelity, openness to children, and the view that marriage is sacred. Differences are found in the understanding of monogamy, indissolubility, and sacramental meaning. The research recommends efforts to inculturate Catholic faith within local culture so that Church teaching can be contextually lived out by the Catholic Muyu tribe. The Church is expected to continue developing family pastoral care and cultural dialogue to strengthen the understanding of the meaning of Catholic marriage.