The studies presented in this article longitudinally examined preschool children's learning behavior, which has received increased attention in recent years because of its positive influence on school readiness. The first study used a statewide database (N = 23,434) to examine whether and how learning behavior changed over time. The second study (N = 275) examined whether children's behavioral adjustment and classroom quality significantly predicted learning behavior baseline scores (learning behavior at the beginning of the preschool year) and rates of change throughout the year. Results from both studies indicated that children's learning behavior became more adaptive throughout the year. Results from the second study suggested that children's shyness was negatively associated with baseline scores and classroom organization was positively associated with rates of change over time. These findings highlight the importance of identifying children who exhibit underactive behavior such as shyness, as well as the potential role classroom quality may play in fostering adaptive learning behavior. (Contains 3 tables.)