Chapter 21 examines marital instability in post-1978 China. Since the 1990s, a growing body of research on marital instability, including divorce, in the People’s Republic of China has emerged. To synthesize this burgeoning body of research, this chapter develops five central themes drawn from empirical studies conducted in the reform and post-reform eras. These themes are: (1) gender thesis; (2) resource thesis; (3) cultural-political thesis; (4) life-course thesis; and (5) psychological thesis. This chapter shows how individual characteristics, family backgrounds, and dyadic similarities and disparities (homogamy/heterogamy) and interactions are linked with marital dissatisfaction, marital conflict, and divorce among married Chinese respondents.