The willingness of families to have children plays a crucial role in long-term population development. Currently, China is experiencing a significant risk of low fertility, with low fertility becoming the prevailing trend.

Under the macro background of the comprehensive liberalization of the ''three-child policy'', this study aims to analyze the willingness of the population to have children and the varying influencing factors across different age groups and establish a foundation for developing pertinent fertility policies by elucidating the concerns about fertility held by various age groups.

The data used in this study was sourced from the 2021 China Comprehensive Social Survey (CGSS). This study selected a population aged 20-44 years old, and after excluding missing variables, a total of 2 525 samples were included, including 1 444 females. A study on the entire population is conducted in order of age from young to old, with one group every 5 years old, for a total of 5 groups; Research on women was divided into two groups based on age groups of 34 and 35 and above. Using multiple variables from three dimensions of personal characteristics, family characteristics, and attitudes as possible influencing factors, an ordered Logistic regression model was used to analyze the factors affecting fertility intention in the entire population and only for women.

The number of people willing to have two children accounted for 59% of the total survey population (1 491/2 525), and the group under 34 years old had a higher willingness to have zero children compared to the group over 35 years old (P<0.05). The results of Logistic regression analysis showed that, among individual characteristic variables, individuals with better health conditions were more likely to have a higher willingness to have children, which was significant in the population aged 35-39 and women over 35 years old (P<0.05). In the family characteristic variables, people with a larger family size were more likely to have a higher willingness to have children, which was significant in the population aged 25 and above and women over 35 years old (P<0.05). There was a higher likelihood of having a stable partner with a higher willingness to conceive, which was significant in women under 34 years old (P<0.05). In the concept attitude variables, all variables of the 20-24 were group were significant, and the results showed diversity in other age groups.

The current mainstream fertility intention is to have two children, and the fertility intention of young people (under 34 years old) is relatively high. Better physical health and larger family size are more prominent in the age group of 35 and above, and attitudes have a stronger impact on fertility intentions, with significant age differences. It is recommended to pay attention to the reproductive views of different age groups, strengthen family, social, and policy support, attach importance to women's physical health, and provide medical support for childbirth.

家庭生育意愿关系到人口的长期均衡发展，当前我国面临较大的低生育风险，低生育现象已成为常态。

在全面开放三孩的政策背景下，通过分析人群的生育意愿以及其在不同年龄段的影响因素差异，明晰不同年龄人群对于生育的顾虑，为相关生育政策的制定提供依据。

本研究采用的数据来源于2021年中国综合社会调查（CGSS）。本研究选取年龄为20~44周岁的人群，剔除缺失变量后，共纳入样本2 525名，其中包括1 444名女性。针对全人群的研究按照年龄从小到大的顺序每5岁为1组，共计5组；针对女性的研究，按照年龄≤34岁和≥35岁为标准分为两组。以个人特征、家庭特征、观点态度3个维度的多个变量为可能影响因素，使用有序Logistic回归模型分析全人群以及仅针对女性的生育意愿影响因素。

意愿生育二孩人数占总调查人数的59.05%（1 491/2 525），≤34岁人群相较于≥35岁人群生育0孩的意愿更高（P<0.05）。有序Logistic回归分析结果显示，个体特征变量中，35~39岁人群和≥35岁女性群体中健康状况更好的人生育意愿高的可能性更大（P<0.05）；家庭特征变量中，≥25岁人群和≥35岁女性群体中有更多家庭人口数的人生育意愿高的可能性更大（P<0.05）；≤34岁女性群体中有稳定的伴侣生育意愿高的可能性更大（P<0.05）；观念态度变量中，20~24岁人群所有变量有显著性，在其他年龄组的结果表现出多样性。

意愿生育二孩为当下主流生育意愿，以≤34岁为代表的年轻群体低生育意愿相对较高。更好的身体健康状况和更多的家庭人口数在35岁以上年龄段结果更突出，观念态度对生育意愿影响较强并且年龄差异明显。建议关注不同年龄段人群的生育观，加强家庭、社会和政策支持，重视女性自身的身体健康，提供生育医疗保障。