Using the one percent samples of the 1990 China Census from Beijing and Xinjiang and binomial logistic regression method, we examine the ethnic intermarriage patterns among the national. minority groups in Beijing and Xinjiang. The number of married couples analyzed is 22,909 in Beijing and 27,811 in Xinjiang. The findings generally support Blau's (1971) proposition about group size. After taking into account the effects of age, education, urban-rural residency and geographic distribution, in Beijing the Manchu, the Hui and "other" nationalities are significantly more likely to marry out than the Han (all p < 0.001); in Xinjiang the Kazakhs, the Hui, the Uighur females, and "other" nationalities are more likely to marry out than the Han while the Uighur males are less likely to marry out than the Han males (p < 0.05). A great deal of variation exists among the minority groups, however. The Manchu are the most exogamous, and the Uighurs are the least. Social, political, cultural, linguistic, and religious factors are important factors affecting the likelihood of out-marriage for minority nationalities.