Japan should settle on the environment and the development integration support strategy for cooperation in not only environmental ODA but also various fields to support the achievement of Sustainable development in the developing country. When the support strategy was settled on, the classification by countries investigation was executed aiming not to limit to an environmental arena in the narrow sense like the atmosphere and the water quality, etc., and to do the investigation including in the wide sense environmental arenas of the agriculture, forestry and fisheries resource, the water resource, energy, and the natural deterioration, etc. The classification by countries investigation concerning environmental cooperation assumed the emphasis of the investigation to be a field the key problem of the object country and the surrounding area, and was done contributing to the decision of "Environment and development integration support strategy", and aiming at the material of the classification by countries program of assistance decision that the government settled on.