This study developed a Japanese version of the Child Social Preference Scale, which measures children's social withdrawal. In addition, we examined developmental changes of children's withdrawal and the relationships between withdrawal and problematic behaviors. The participants were 7 012 mothers of preschool, elementary school, and middle school children. A factor analysis revealed a two-factor solution of shyness and social disinterest, which is consistent with previous studies. Shyness decreased as children's grade level increased. Social disinterest changed in a quadratic manner. The shyness score was lowest in the lower grades of elementary school. Shyness was related to more emotional symptoms, more peer relationship problems, and less prosocial behavior. Social disinterest was related to peer relationship problems. The importance of the distinction between shyness and social disinterest is discussed.