This research compared the effects over time of parents' control and autonomy support on children's functioning in the United States and China. American and Chinese (N = 806) seventh graders (mean age = 12.73 years) participated in a 6-month longitudinal study. Children reported on their parents' psychological control, psychological autonomy support, behavioral control, and their own emotional and academic functioning. Children's grades were obtained. Supporting cultural similarities, in both countries over time, parents' psychological control predicted children's dampened emotional functioning, parents' psychological autonomy support predicted children's enhanced emotional and academic functioning, and parents' behavioral control predicted children's enhanced academic functioning. Supporting cultural differences, the beneficial effects of parents' psychological autonomy support were generally stronger in the United States than in China.