Sociological and demographic analyses of minority fertility in the United States have suggested that the processes of socioeconomic, cultural, marital, and structural assimilation will lead to convergence in fertility. So far, little research has used the assimilation approach to study the fertility of the minority populations of China, and also, no research has taken both individual-level and group-level characteristics as predictors. Using micro-data from the One Percent 1990 Census of China, this dissertation performs multilevel analyses, hierarchical generalized linear modeling, to examine the effects of assimilation and the one-child policy at both the individual level and the group level on minority women's fertility. Several patterns are found in the multilevel analyses. First, the contextual characteristics of minority groups have strong correlations with fertility across thirty major minority groups in China. It suggests that community power and subculture have strong influences on women's decisions regarding their number of children. Second, the effect of the one-child policy is positive and highly significant on minority women's fertility. However, the strong policy effect does not cover the effect of assimilation. After controlling for policy, the impact of all the assimilation predictors, at both the individual and group level, still remains statistically significant. At the individual level, minority women's educational level, occupational status, status of intermarriage, and migration status have significant and positive impacts on their fertility. At the group level, the levels of minority groups' residential segregation, educational segregation, illiteracy, intermarriage rate, and their Moslem group culture have significant and negative impacts on individual women's fertility. Third, several cross-level interactions in the rural models are not consistent with the complete models, which suggests that some indirect effects of assimilation on minority fertility may come from the urban minorities. Finally, in addition to the direct impacts of socioeconomic, marital, and cultural assimilation on minority fertility, several cross-level interactions are significant and indirectly affect women's fertility. Findings reported in this dissertation indicate a successful integration of individual and contextual variables in analyses of minority fertility. The results contribute to the understanding of the assimilation impacts on minority fertility in China.