Over the past few decades, there have been signs of a marriage decline across many world regions. Alongside this trend, individuals increasingly form intimate partnerships or family-like ties outside marriage. Non-marital and alternative family configurations are no longer rare exceptions, but are emerging as significant family forms that coexist with marriage while reshaping the meaning and boundaries of family in everyday life. Chinese families are undergoing profound transformations, as manifested in the growing consensus among younger generations that marriage is no longer “a must” in life. Despite shifting attitudes toward marriage among young people and increasingly diverse forms of intimate relationships, research on Chinese families still centers on marriage.

Drawing on international scholarship and cross-national data, we move beyond a marriage-centered lens to examine three forms of non-marital relationships—cohabitation, living-apart-together (LAT) partnerships, and chosen families (i.e., families defined not by marriage or blood but by mutual support and enduring solidarity). We analyze the trends and organizing logics of these non-marital relationships and consider their implications for China.

The findings reveal that among women aged 30-34, the percentage of the married declined from 99% in 1982 to 88% in 2020 in China, and the corresponding figures fell from 63%-87% in the 1980s to below 50% in 2020-2023 in many Western countries. Despite their unmarried status, many people still “do” family in alternative ways. In 2022-2024, 18%-59% of unmarried adults aged 25-44 had a cohabiting partner in Western countries, compared with around 2% in China. In European countries, 5%-13% of adults aged 18-79 were in LAT partnerships between 2020 and 2024, although comparable figures for China remain unavailable. Evidence from Western scholarship and Chinese public discourse suggests that chosen families are not confined to marginalized groups, but rather represent a common way in which people, especially never-married older women, construct intimacy beyond couple relationships.

Non-marital relationships carry different meanings in the West and China. In Western societies, cohabitation has increasingly become an alternative to marriage, whereas in China it is mainly considered a prelude to marriage. Western LAT partnerships emphasize individual autonomy, yet in China, their formation is shaped more by structural factors such as the household registration (hukou) system. Chosen families in Western contexts are often associated with marginalized groups and viewed as an individualized family form, whereas in China such family practices may be primarily driven by anxiety about old-age care.

This study makes several contributions. It highlights that family change is reflected not only in the transformation of the marital institution but also in the diversification of non-marital relationships. By moving beyond a marriage-centered framework, this study broadens the scope of research on Chinese families. It argues that Chinese families are shaped by the dynamic interplay between structural resilience and practical flexibility. As such, non-marital relationships must be understood in relation to institutional contexts, life-course trajectories, and individual practices. This study advocates for incorporating non-marital relationship modules into large-scale social surveys in China to facilitate research in this area. Foregrounding non-marital relationships, this study enables a more comprehensive understanding of the growing diversity and complexity of family life in contemporary China, while contributing to policy development and theoretical advancement amid rapid societal and family transformations.