This article is divided into three parts. First, I discuss the preaching strategies of the Dominicans and their influence on Taiwanese ethnic groups in 1859. Second, I analyze the structures of local ethnic groups and the great change in Catholicism when Catholics from China moved to Taiwan after 1949. Third, I describe the differences in culture and faith between the three Han groups-the Hoklo, Hakka and Mainlanders. In doing so, I explore their encounter with Catholicism. The paper comes to three conclusions. First, mandarin-speaking Catholics were marked by mainland Chinese culture. The consequences of this can be seen in two areas. Even if their numbers were only one-third of all Catholics in Taiwan, in general, they got a better education and had a higher social status. Moreover, they were also treated better by the local government. Second, evangelism involves cultural dialogue but this was lacking in the case of the Hoklo people. Owing to cultural barriers and unfamiliarity, Hoklo Taiwanese had less chance of getting to know the Catholic faith. A reduction of the number of Masses celebrated in Hoklo shows that dialogue between the Church and the Hoklo people is dying down. In the long term, the impact of missions out of Hoklo communities was negative. Third, Hakka Catholic communities did not develop their own characteristics. The piety of the priests and experiences of the faithful did not interact with the traditional group identity of the Hakka. The reason why the number of Hakka Catholics has declined sharply may be that the faith was not rooted in traditional Hakka culture.