This research examined the idea that children's parent-oriented motivation underlies the benefits of parents' involvement on children's engagement and ultimately achievement in school. Beginning in the fall of 7th grade, 825 American and Chinese children (mean age = 12.73 years) reported on their parents' involvement in their learning as well as multiple dimensions of their motivation in school every 6 months until the end of 8th grade. Information on children's self-regulated learning strategies and grades was also obtained. Over time, the more involved parents were in children's learning, the more motivated children were to do well in school for parent-oriented reasons, which contributed to children's enhanced self-regulated learning and thereby grades. Although children's parent-oriented motivation was associated with their controlled and autonomous motivation in school, it uniquely explained the positive effect of parents' involvement on children's grades. (Contains 2 tables and 3 figures.)