China has long been a society of universal marriage, where “people should marry when they reach maturity” has been a common consensus among its citizens.Over the past decade, the number of registered marriages in China has plummeted, and by 2024, the number of marriages was only 45.33% of the 2013 level, which has become an important factor contributing to its negative population growth. Using data from the population censuses in 1990, 2000, 2010 and 2020, this paper applies logistic models fitted with Python to analyze the trends in unmarried rates over the past three decades and compares the distributional characteristics and changes in the unmarried rates across different population groups. The findings show that, first, among people of marriageable age, the proportion of unmarried individuals has been rising year by year and the time required for the population to complete the marriage process has become increasingly prolonged. Although the number of those who never get married has remained basically stable, the universal marriage age has been significantly postponed. Second, the imbalance in the gender ratio in the marriage market has subjected young men to severe marriage squeeze, with low-educated men becoming the most affected group and exhibiting significantly higher unmarried rates than other groups. Among cohorts born after 1995, the imbalance in the gender ratio is even more serious, and the marriage squeeze on low-educated men caused by the gender structure is likely to worsen further. Third, the dispersion of unmarried rates across educational groups has increased; higher levels of education postpone the age at first marriage, but apart from those with primary schooling or below, there is no significant difference in the final unmarried rates across other educational levels. Fourth, among low-educated groups, the unmarried rates of men are far higher than those of women, whereas among highly educated groups, the distributions of men’s and women’s unmarried rates are almost identical, indicating that higher educational attainment has eliminated gender differences in unmarried rates. Fifth, among those with junior-college education and above, the proportion of women who ultimately never marry is higher than that of men, indicating that the issue of “highly educated leftover women” is not a pseudo-problem. To promote marriage formation among young people in China, this paper proposes making the building of a marriage-friendly society an important component of broader social development.