The purpose of this study was to investigate the level and the reasons of son preference, and the relative importance of related variables among middle-and old-aged Koreans in Chon-buk and Chung-nam area. Subjects were 487 parents of high school girls(243 fathers and 244 mothers), with a mean age of 45.7 years. It was revealed that more than a half of the respondents (52.2%) preferred `a son` for the first child, followed by `either sex`(32.6%) and `a daughter`(14.8%). For the second child, a son was preferred most(43.7%), followed by `a daughter`(31.4%) and `either sex`(23.4%). As the reasons of son preference, `to continue tradition and name of family` marked the highest score (3.42), followed by `parents prefer son for various reasons`(3.37), `should have at least one son`(3.32), and `feel obliged to produce a son for in-law`s sake`(3.06). It appeared that sociocultural background was more important for son preference than individual, economic factors. The most important factors related to a strong son preference were the number of sons at the present, son preference for the first child, parental attitudes and expectations toward children, and income. Suggestions were made in regard to efforts for gender equality in family and society, and the needs for parent education and population education.