This article examines the evolution of family and marital structure in modern China in the light of changes in China's culture, changing government policy and changes in the attitudes and situations of modern couples and families. The most dramatic changes involved the one-child policy, instituted in the late 1970s, that changed family structure from large male-preference families to single child families that enhanced the value of girls. Since sex was no longer mainly for procreation, it also revised the role of sexuality. The result was both to pamper the “only children” and increase the pressure on them both as children and as young adults, because this policy produced an ageing population without enough workers. The recent change in government policy to allow three children has not altered median family size as many young people do not want more children. There is also the lingering effect on families of China's history of trauma. Several clinical vignettes illustrate the complex mixture of forces at play in modern families.