Despite a rapidly growing body of literature on marriage behaviors in China, we know very little about the changes or continuities of marriage values that accompany or underlie these behavioral transformations. Using nationally representative samples from the 2006, 2010, 2012, and 2013 Chinese General Social Surveys (CGSS), we investigate the patterns and determinants of marriage values across birth cohorts of men and women. Analyses reveal an increase in acceptance of premarital sex, same-gender sex and cohabitation across birth cohorts, but little change in attitudes toward singlehood and out-of-wedlock childbearing, and a slight decline in approval of divorce. Educational attainment and exposure to Western values, measured by Internet usage and English proficiency, are positively related to approval of premarital sex, cohabitation, and same-gender sex, but have no effect on acceptance of out-of-wedlock childbearing. Moreover, attitudes toward premarital sex and cohabitation show a widened gender gap across birth cohorts, with men showing a greater increase in acceptance than women. The results suggest that the Chinese marriage institution has had a unique pattern of evolution that is distinct from that of marriage in Western society. Desire for the traditional cultural ideal of forming and continuing a family has been unwavering, leading to early and nearly universal marriage. At the same time, longing for increased personal freedom and individualized property rights has weakened the marriage institution in China as manifested in increasing rates of divorce and marital infidelity. We discuss the paradox seen in marriage values and behavior resulting from the influence of state regulations, traditional ideologies, and Westernization.