The country saw 6.1 million couples register for marriage in 2024, down from 7.7 million the previous year, according to data published by the Ministry of Civil Affairs.

The 20.5 percent drop coincided with the third consecutive year of overall population decline in China, which in 2023 was surpassed by India as the world's most populous nation.

China's population of 1.4 billion is now rapidly ageing, with nearly a quarter of people aged 60 or above as of the end of last year.

The demographic trends present fresh challenges for authorities in the country, which has long relied on its vast workforce as a driver of economic growth.

The slide in marriages comes despite a pro-family campaign rolled out in recent years by Beijing, which has included various subsidies and messaging encouraging people to have children.

But experts say that higher costs -- especially for education and childcare -- and the challenging employment market awaiting fresh graduates are among factors discouraging would-be parents.

"If I don't rely on my parents, I simply can't afford to buy a house, and getting married is also a huge expense," commented a user of Chinese microblogging site Weibo under a news post about the data.

"This year I suddenly feel that being single is also pretty good. There's not so much pressure, I earn and spend my own money," the user added.

In the 1980s, Beijing imposed a strict "one-child policy" as overpopulation fears mounted. The rule was only ended in 2016.

Couples were allowed to have three children in 2021, but signs of China's demographic reversal had already begun to emerge.

Declining marriages in the world's second-largest economy threaten to exacerbate pressure in coming years on pensions and the public health system.

In a long-anticipated move, Beijing announced in September that it would gradually raise the statutory retirement age, which -- at 60 -- had been among the lowest in the world.