Objective : The purpose of this study is to find out how the task performance ability of children with developmental disabilities affects intervention and to provide basic data for the establishment and effective progress of intervention programs according to the difference in initial task performance ability of children with developmental disabilities. Methods : The initial task performance ability of children with developmental disabilities was observed for two months from October 2022. The receipt of intervention and the enactment of treatment skills during intervention fidelity for two months were analyzed through a survey by occupational therapists. The general characteristics of children with developmental disabilities and caregivers were set as control variables, and the effect of task performance on intervention was analyzed through statistical programs. Results : First, the results of this study showed that there were significant economic level of caregivers, the age of children with disabilities, and the degree of disability in comparing task performance according to general characteristics. Second, in the comparison of interventions according to general characteristics, there were significant final education of the caregiver, the economic level, the age of children with disabilities, and the degree of disability. Third, self-regulation & decision-making, and basic learning skills were found to affect intervention in the effect of children with developmental disabilities' ability to perform tasks on intervention. Conclusion : It was found that the task performance ability and intervention of children with developmental disabilities changed according to the direct and indirect factors of children with disabilities, and the initial task performance ability affected the intervention.