Because the cost of divorce, such as losing property and suffering mentally, can be onerous, some people opt not to marry, she says.

Longevity may also be deterring people from marrying, she says. In ancient times people lived much shorter lives, so questions of how long they would be married were less important when deciding whether to do so. However, now the average life expectancy in China is 74 for men and 77 for women, and for some the idea of making a commitment lasting many decades may be too much to contemplate.

The awareness of greater gender equality may be another factor, Li says. In the past, most Chinese women were not in paid employment, so they were under greater pressure to marry as a matter of economic necessity.

Legal changes that reflect changing social mores may also be playing a role in reducing the pressure to marry. Until eight years ago in China, it was a criminal offense for two people who were not married to one another to engage in sex.

"Before that, unmarried couples might have been afraid to have sex, fearing the consequences," Li Yinhe says. "The pressure was huge."

She suggests that single people lower their expectations for what they want from a partner or simply get on with enjoying single life.

"Affinity is the most important thing. Being single is simply a life-style choice."

Another aspect to the issue is the question of single women's reproductive rights.

In China, because of family planning policies, only married women can obtain a hukou, or household registration, for newborn.

In 2002, family planning rules in Jilin province, in the northeast, were changed so single women of legal marriageable age who have no children can legitimately have a child. Jilin is one of the few jurisdictions in China that has such rules.

Li Yinhe says there should be a specific law to ensure single women's rights to give birth. Women are endowed with reproductive rights, and single women are capable of adhering to family planning rules, she says.

She suggests the government improve retirement, pension and medical systems to guarantee the rights of unmarried people.

Luo says she plans to urge representatives to submit a proposal at the National People's Congress and Chinese People's Political Consultative Conference next year to safeguard the reproductive rights of single women.