The proposed study will evaluate social determinants on health by investigating how social support systems are associated with stress levels and quality of life of families with children with developmental disabilities. Our study is joint research being carried out in Japan and New Zealand. We agreed to 1) conduct a baseline questionnaire survey to establish the initial conditions of social support, parental stress, and quality of life in both Japan and New Zealand; and 2) develop further in-depth qualitative research strategies on the basis of the survey findings and conduct a pilot study with the developed strategies. The research findings will be disseminated not only in international peer reviewed academic journals, but the researchers will also provide a report to Ministers of Health, Education, and Social Development (in Japan) and the Ministry of Health (in New Zealand) on research-based recommendations to improve health and disability support services and to inform policy-level decision making. The findings will also be made available in seminars and workshops for service providers in Japan and New Zealand.