In this paper we use data from the 1 Per Cent Sample of the 1990 Census of China to calculate sex ratios for the Chinese provinces that are specific not only to parity, but also to the sex composition of previously-born children. We analyze the degree of relationship among and between the SRB's and then consider the phenomenon of son preference. We find the variation in sex ratios at birth among the Chinese provinces is related in an important way to variation among the provinces in the degree of son preference. Our analysis shows abnormally high SRB's in most of the provinces of China, especially at parities 2 and higher when the prior births were daughters. Other societies, namely Taiwan and South Korea, with rapid fertility decline and strong son preference also manifest abnormally high SRB's at parities beyond the first.