In-depth interviews with twelve Mosuo mothers of three generations and three Mosuo maternal uncles from fifteen Mosuo's matrilineal households in the Yongning administrative village of Yunnan province, China were analyzed using Parsons' (1955) role-structure and Mischel's (1966) social learning theory from structural functionalist's perspective. The conclusion reached is that in Mosuo's matrilineal family system, mother's role is defined as both instrumental and expressive, maternal uncle's role is defined as instrumental, grandmother and grand maternal uncle's role is defined as expressive, and biological father's role is defined as expressive. This role allocation structure makes Mosuo mothers economically independent; makes Mosuo maternal uncles and biological fathers also economically independent, but not able to control the two roles they are supposed to play simultaneously, and Mosuo men therefore enjoy less power and take less responsibilities in both their mothers' families and their wives' families. The culture socialized in Mosuo's matrilineal family system can be defined as grand household oriented and women centered culture, which values feminine traits, and which makes Mosuo women enjoy more power and take more responsibilities in their families. Therefore, the mechanics of role allocation and children's socialization balanced Mosuo men and women's power and status in Mosuo's matrilineal family system.