||This paper examines the trend in marriage formation in the context of changing socioeconomic inequality between men and women in Hong Kong since the 1980s. Results show a narrowing gender gap in educational attainment, labor force participation and earnings over the past a quarter century and also an increasing proportion of delayed marriage and non-marriage in Hong Kong. Using the sample data from Hong Kong population censuses and by-census from 1981 to 2006, the paper aims to link these demographic processes and test three main theories on marriage formation: economic independence theory, modernization theory, and marriage market mismatch theory. Results show that, firstly, while labor force participation decreases the likelihood of remaining unmarried for men, it increases the likelihood of remaining unmarried for women. Furthermore, among those women who participate in labor force, there is no significant effect of earnings on the likelihood of getting married from 1981-2001 and significantly positive effect in 2006. Secondly, education increases the likelihood of remaining single, both for men and for women: the more education one has received, the more likely he or she remains single. Finally, as the pattern of educational assortative mating has not changed, the increase in female education and reduced gender gap in educational attainment have led to a mismatched marriage market, where highly educated women could hardly find potential spouses who are preferred to have even higher education. The paper concludes that the structural changes in the marriage market is the main cause of the rising delayed marriage and non-marriage in Hong Kong.