Using longitudinal data from the National Institute of Child Health and Human Development Study of Early Child Care and Youth Development (N = 1,088), we examine changes in maternal perception of closeness and conflict in the mother-child relationship from the child's preschool to adolescent years, with attention to variation by maternal education. Analyses using individual growth models show that mother-child closeness increases, while mother-child conflict decreases from preschool to first grade. From first grade to age 15, mother-child closeness decreases, while mother-child conflict increases, both gradually. The decrease in mother-child conflict from preschool to first grade and the increases in mother-child conflict from first to fifth grade, sixth grade, and age 15 are less steep for mothers with a college degree than for mothers without a college degree. These findings underscore the importance of examining changes in parent-child relationships using longitudinal data across children's developmental stages and their variations by parental social and economic status.