The paper described the present situation of the waste treatment system for the environmental engineering and the problems. The final waste treatment plants are in the tighter and tighter condition, and therefore the waste treatment system ought to be changed to a system in which importance is placed on the size reduction, weight reduction, and recycle. Accordingly, the waste treatment system becomes more characterized as a resource feedback process, and should be given more credit as a system for production of secondary resource. The problem is arrangement of conditions of technology, cost and legislation system for smoothing such recycling flow. Of course, it is natural that the most important subject of the system is to secure the environmental preservation by the waste treatment. As future subjects, needed are understanding of the waste treatment as a resource reproductive system, relation with other industries, and review of the legislation system. In consideration of technology, cost and environmental loads, required are proposal of validity of the recycle level limit and a future image of the system structure, and policies for promoting and supporting the recycle business. 47 figs., 104 tabs.