The study analyzed the mediational model of relationship between mothers’ motivational beliefs, type of involvement (autonomy support and control) in homework, and the children's learning-oriented purposes for doing homework. The sample included 235 boys (M age = 11.09, SD = 0.56 years old), 273 girls (M age = 11.12, SD = 0.62 years old) and their mothers (M age = 37.85, SD = 6.94 years old) from Mexican elementary schools. Two structural models were calculated. The first model indicated that mothers’ mastery-oriented goals and self-efficacy had a positive relationship with the support of children's autonomy and a negative one with mothers’ control on children's homework. On the other hand, the mothers’ active role in education resulted negatively related to mothers’ control. Whereas mothers’ performance-oriented goals resulted negatively related to the support of children's autonomy, they were positively related to control. Overall, mothers’ mastery-oriented goals, and self-efficacy had a positive direct and indirect association with children's learning-oriented purpose in homework whereas performance-oriented goals resulted negatively. The alternative model indicated that children's learning-oriented purpose for doing homework promoted mothers’ mastery-oriented goals, self-efficacy, and an active role in education in mothers; in turn, it hinders their performance-oriented goals. In addition, it had positive direct and indirect associate to autonomy support, but not affected control. Overall findings suggest a reciprocal relationship between mothers’ characteristics and children's motivation for homework.