The current study recruited seven 4th-grade students (9-10-year-olds) from elementary schools. The participants were referred by their teachers due to their socially withdrawing behaviors. Research participants were randomly assigned to an experimental group (n = 3) or a control group (n = 4). A pretest-posttest experimental design was utilized in this study. Participants in the experimental group received individual child-centered play therapy once a week for 10 weeks, while participants in the control group did not receive any intervention. All research participants were administered by three questionnaires including Child Behavior Checklist for Ages 6-18(CBCL), Teacher’s Report Form for Ages 6-18(TRF), and Children’s Self-Concept Questionnaire one week prior to and one week after receiving child-centered play therapy. All data was entered into SPSS and analyzed by non-parametric statistics (i.e., Mann-Whitney U test). In addition, in-class observations were conducted twice a week for sixteen weeks. Data from direct observations were examined by visual analysis. The main results of the current study included the following: (a) Child-centered play therapy significantly decreased withdrawn behaviors among socially withdrawn children; (b) Child-centered play therapy did not show instant improvement on socially withdrawn children’s self-concept; and (c) Positive process changes occurred in socially withdrawn children after receiving child-centered play therapy.