Comparisons of migrants vs. native populations have become increasingly important as a means of gaining insight into the factors affecting health and mortality levels and the relationship between them. Taiwan underwent a unique migration in 1949-50, as more than a million people, mostly young males, arrived from Mainland China following the Communist civil war victory. The Mainlanders are distinct in several ways: they represented different provinces in China than the original settlers, were better educated, and had distinct occupational profiles. Since 1950, Taiwan has experienced a rapid demographic transition and notable economic development, resulting in mortality decline. In this paper, we generate age- and cause-specific death rates circa 1990 by education and nativity to evaluate the relative importance of each factor. We also use time series data on mortality and survey data to help interpret the differentials in terms of selection, risk factors, and other dynamics of health and mortality.