The Second Demographic Transition (SDT) is a useful theoretical framework for explaining the recent trend in many countries of very low fertility combined with alternative union and family types. Although past studies have observed the SDT in many Western societies, whether it is applicable to East Asia remains unclear. Capitalizing on data from the Chinese Census and China Family Panel Studies, we provide estimates of key behavioral and ideational indicators of the SDT. We find that union formation in China has trended increasingly toward patterns commonly observed in the West, including delayed age of marriage and the common practice of premarital cohabitation. While having a lowest-low fertility rate, China has not experienced rising nonmarital childbirths, a key component of the SDT. However, we observe growing tolerance toward nonmarital childbearing and childlessness. Marriages remain relatively stable in China, especially among couples with children. Taken together, our analysis suggests that typically coincident changes in patterns of family behavior associated with the SDT are not occurring simultaneously in China. Moreover, ideational changes are preceding behavioral changes, particularly in attitudes toward nonmarital childbearing and childlessness. Our research suggests a different pattern of the SDT in China, which has been heavily influenced by Confucian culture.