The psychologists for reducing child behavioral problems have suggested many different methods. Some of these methods have focused on child, some on parents and the others on educational environments. The most prevalent way for changing the child behaviors has been play therapy.In the last decades, play therapy has been focused more on the therapist-child relationship, whereas some methods have been attended to educat-ing play therapy skills to parents as an intermediate for improvement of child behaviors. One of these methods is child-parent relationship thera-py (CPRT).The aim of this research is surveying the efficiency of CPRT on reducing child problematic behavior. For surveying this aim, some preschool children aged 6-7 were assessed in two phases. In the first stage 73 chil-dren have been assessed using Child Behavior Checklist (CBCL), that 25 children had behavioral problems. 13 of their mothers were ready to contribute in this research that 6 mothers have been randomly assigned to experiment group and 7 to control group.All of these mothers filled the CBCL in pre and post test situations. The experiment group faced with play therapy skills training program in ten two-hour session and the control group waited for an optional delayed treatment. Pre and post test data was analyzed with U-man witney test and the results showed that CPRT has caused a meaningful reduction in children's behavioral problems in experiment group than control one.