Recently, it is difficult to incinerate MSW(Municipal Solid Waste) because of dioxin emission, imposing strong restrictions on the air pollution and incineration scale. The RDF (Refuse Derived Fuel) system is worthy of notice as an alternative disposal. But RDF has not enough demands(ways of use) yet like generation of electric power, thermal supply of DHC (District Heating & Cooling). This paper analyzes the possibility of RDF as an aid fuel of DHC system with two viewpoints of environmental loads and social economic value in total process. Environmental loads are analyzed into LCI(Life Cycle Inventory) concept that is the measure of environmental loads from exploitation of raw material to the final disposal in some system or material. At first, RDF manufacture and Incineration(Energy Recovery) processes are identified with LCI, a more low level emission and efficient energy recovery than an existing system, and then compare DHC system using RDF as an aid fuel with fossil fuel use system. As a result, he total analysis showed that the RDF system is a more low environmental load and high social economic net value than the existing system.