The 2300,0000 population in Taiwan may be broadly classified into four ethnic groups: Hoklo, Hakka(4000,0000), Mainlander(3500,0000) and aborigines(35000). In the four ethnic groups, the relationship between Hoklo and Hakka is most concern. In the interaction, they have been fighted, also have been against the regine. And it has a special ethnic group which name is Hoklo Hakka. It means that Hakka was assimilation by Hoko. We have a conclusion, that is ethnic assimilation is very important. They must be harmony. Then our country has a good development.