"Marriage Laws and Practices in South China, 1930-1980" traces and compares different models of state regulation of marriage via laws and campaigns and people's responses over five decades. It focuses on twentieth-century South China, a time and place in which successive regimes in China and a colonial government in Hong Kong each tried to reform marriage customs, with differences in scopes and methods across the Hong Kong–China border. In China under the Nationalist and collaborationist regimes and under the Communist Party in the People's Republic of China, the national government and its provincial counterpart adopted an active agenda to reform marriage, in contrast to the laid-back approach by the post-war colonial government in Hong Kong. Through analyzing changes in marriage customs in the context of three marriage laws--the Nationalist Civil Code in 1930, the People's Republic of China Marriage Law in 1950, and the Marriage Reform Ordinance in Hong Kong in 1971, this dissertation crosses the chronological divides of the establishment of the PRC in 1949 and the end of the Cultural Revolution in 1976. It suggests that regime changes or political campaigns had a real but limited effect on changes in habits and customs. Furthermore, the regional specificity of South China and cross-border marriages in China and Hong Kong during the Maoist era made marriage governance more challenging for the state, as the people were less receptive to the state's message of frugal weddings and transaction-free marriage. Gradually the state in China evolved into a regulatory behemoth, and its people's ability to act outside the law gradually diminished as state capabilities to regulate marriage expanded between the 1950s and the 1970s. Nonetheless, urban and rural residents frequently found ways to manipulate politics and policies while interacting with multiple levels of the Chinese state (local, provincial, national) and the colonial state in Hong Kong to retain their marriage practices and customs despite relentless campaigns from the top.