The study is about the missionaries and the beginning of Modern Education among the Sayyo Oromo who live in Dambi Dollo and its surrounding. The study attempts to document how the Missionaries, especially the Protestant Missionaries came to the area of Sayyo and their methods of expansion as well as how they undertook the conversion activity among the Sayyo Oromo The study also deals with what the traditional religious and ritual ceremollie of the Sayyo people looked like before the introduction of either Christianity or Islam in to the area. Further investigation was also conducted to check how the Ethiopian Orthodox church expanded in the area and how it was welcomed among the Sayyo Drama. Furthermore the study tried to check how the Ethiopian Orthodox Church, the first Christian Church, which had penetrated the Sayl'o area and how if responded to the newly arrived Protestan tism as well as the relationsh ip between the Ethiopian Orthodox Christians and the Protestants. In this study special focus is given to the Missionaries modernizing efforts among the Sayyo Oromo. That means how Missionaries started building Schools, Hospitals, Clinics and different Churches. Despite the efforts of the missionaries in expanding modernization among the Sayyo Oromo they had also affected the normal life-style of the people. The research reveals that Christianity arrived among the Sayyo Oromo of Dambi Dollo and it urroundings before a century ago. Protestantism expanded in the area by convincing methods of donation and often by impressive pressures made particularly through attacking the traditional Oromo religion with its rituals. In genera! the contextual background, Political oppression, low economic status, lack of infrastructure, the event of Influenza Epidemic and other world historical events contributed to the people.,·' active conversion to Protestantism The mass conversion of the people resulted in creating new spiritual orientation, which brought about holistic change, including the undermining of indigenous cultural practices.