In recent decades, marriages between Taiwanese men and non-Taiwanese women were relatively common. Because such marriages often involved less educated and rural Taiwanese men, there were concerns regarding theses couples' disadvantaged positions in Taiwan and how their spouses, mostly from mainland China and Southeast Asia, fared and integrated in Taiwan. Using data from the Life Survey of Foreign and Mainland Spouses in Taiwan in 2003, 2008, and 2013, along with data from the Taiwan Social Change Survey, we compare educational assortative mating patterns over time among marriages between men in Taiwan and women in Taiwan, Southeast Asia, mainland China, Hong Kong, Macau, and elsewhere. Over a period of about fifteen years, less educated Taiwanese men became much less likely while highly educated Taiwanese men became more likely to marry or form cross-border marriages with spouses from mainland China and Southeast Asia. Furthermore, we apply log-linear models to study how educational assortative mating patterns have shifted over time, as a result of improvement in economic position in places such as mainland China and Southeast Asia. Our analyses reveal that less educated Taiwanese men were able to exchange Taiwan's economic position, not their own, for marriages with women from mainland China and Southeast Asia, formed between 1998 and 2003, but over time, educational assortative mating patterns involving men from Taiwan and women from mainland China, and to a less extent, from Southeast Asia have become similar to the patterns among marriages between men and women in Taiwan. We argue that improvement in economic position in mainland China and Southeast Asia has reduced the prospects of marriage for less educated Taiwanese men and cross-border marriages have presumably become more based on love, through contact opportunities, as seen among Taiwanese marriages. One implication is that newly formed cross border married couples become less likely to live at the bottom of the Taiwanese society and lack of marriage prospects among less educated men in Taiwan may become another form of social problems.