This study examines marital construction of family power among male-out-migrant couples in a Chinese village in Guangxi Province. In-depth interviews show that male-out-migrant couples prefer joint decision making. When couples are in disputes, power tends to go to the ones who shoulder greater household-based responsibilities; in this case, they are mainly married women. The couples achieve power-responsibility congruence by following relation-oriented exchange, which emphasizes spouses' obligations to the family and relational harmony, as opposed to equity-oriented exchange, which stresses the importance of comparative resources in one's ability to wield power. Consequently, family power among male-out-migrant couples is group serving and enhances marital harmony. However, married women's greater family power constrains as well as empowers them precisely because of the power-responsibility congruence. The unique power processes generated from relation-oriented exchange observed in this study are attributable to ecological and institutional constraints facing the village couples. (Contains 2 tables and 6 notes.)