Objectives: The purpose of this study is to examine the effects of care burden among mothers of children with developmental disabilities on depression and the moderating effects of formal and informal social support. Method: The self-report questionnaires were administered to 200 mothers of children with developmental disabilities (aged 6∼20 years) in pre-adulthood in Gyeongi-do. A hierarchical regression analysis was conducted. Result: First, There is a need to provide a mental health program that can relieve depression. Second, Individualized intervention strategies for mothers' psychological counseling and support programs for intensive case management and parenting stress management programs are needed. Third, Individual visit case management is required. In addition, it is necessary to expand the eligibility for care services and to maintain long-term programs. Conclusion: The findings suggested that there is a need to provide mothers with not only personal assistance program but also services such as mothers' psychological counseling, peer mentor program, and parenting stress management.