China is a multiracial country, where ethnic relationships directly affect the national unity, social stability and national prosperity. For this reason, inter-ethnic marriage, a marriage between persons with different ethnic backgrounds, is not only important but also plays an important role in promoting national unity and economic development. Inter-ethnic marriage affects ethnic relations, increases inter-ethnic exchange of ideas, accelerates the development and inheritance of national culture, and promotes national reproduction and integration. Inter-ethnic marriage among the 56 ethnic groups in China has gradually grown. Marriages involving the 55 ethnic minorities and the majority group (Han) exceed 90% of the total inter-ethnic marriages. Given the rapid economic development and migration, it is likely that inter-ethnic marriage will continue to grow. Analyzing the 1% sample data from the 5th census of China in 2000, this study examines inter-ethnic marriages in three provinces; Guangxi, Guizhou, and Xinjiang. These provinces are selected, since they are not only large enough in population size, but also their populations are the most heterogeneous in the ethnic composition. The number of married people in the data set is 536,226 (or 268,113 couples). Among these couples, about 3% (8,949 couples) turn out to be intermarriage couples.. This study analyzes both macro and micro factors of inter-ethnic marriage. Among the three provinces, Guangxi and Guizhou have similarities in the geographical, cultural, religious and other aspects, so that the patterns of inter-ethnic marriage are expected to be similar. In contrast, Xinjiang is very different from the other two provinces. The boundaries among ethnic groups within Xinjiang overlap with several other important boundaries, including religious, cultural, and linguistic ones. Furthermore, the ethnic groups tend to be separated with regard to residence, and even appearance is different. Because of the higher level of the consolidation, the intermarriage patterns in Xinjiang are expected to be much different from the other two provinces. From the macro structure level, Guangxi and Guizhou show, as expected, similar results. First, the actual (observed) intermarriage is much less frequent than the expected intermarriage, and this tendency of homophily is quite comparable between the two provinces. Second, the majority group (Han) shows a higher level of endogamy than minority groups. Third, men are more likely to inter-marry than women among the Han, whereas the opposite is true among minority ethnic groups. These results are visibly different in Xinjiang. The level of endogamy is much higher there, not just the majority group but also minority ethnic groups. This means that ethnic homophily is much stronger. Analyzing the micro factors of intermarriage via logistic regression, Guangxi and Guizhou Province still show similar trends. A couple is likely to be inter-ethnic, as 1)the age gap between the spouses increases, 2)the level of education increases. In Guangxi Province, I also find that a couple is likely to be inter-ethnic, as spouses are different in their types of registered permanent residence, and they are not the case of the first marriage. However, due to the consolidation of the parameters of Xinjiang Province, no such tendencies are found, with a single exception, the education level of women, which has a positive effect on intermarriage.