This study was to investigate how experiencing activities to foster self-esteem affects young children s Preschool Adjustment. For the purpose, following research questions were how does experiencing activities to foster self-esteem affect young children s preschool adjustment? Participants for this study were 38 five-year-old children in Cheonan, Chungnam. One class of nineteen children(seven boys and twelve girls) was the experimental group and the other class of nineteen children(nine boys and ten girls) was the control group. A questionnaire was used to collect data. The questionnaire was ‘Preschool Adjustment Questionnaire(PAQ)’ translated/revised by Kim (2003). The researcher constructed the activities to foster self-esteem which consisted of 18activities appropriate for syoung children s Preschool Adjustment in reference to the Program Fostering Young Children s Self-esteem (Nokuwon and Nokurang Clinic, 2006), the Self-Growth Group Counseing Program (Oh, 2000), and the Project Spectrum (Krechevsky, 1998). Results of this study were as follows: First, there was significant group difference of young children s Preschool Adjustment by experiencing activities to foster self-esteem between the experimental and control groups, p < .05. Specifically, among those sub-categories of young children’s Preschool Adjustment, significant group difference of prosocial behavior by experiencing activities to foster self-esteem between the experimental and control groups(p < .01).