In order to investigate the influence of drying process on waste heat recovery system, the small-scale incineration system of municipal wastes was designed and the various operation condition and its consequent performance was studied. Small city producing 12~15 tons/day of municipal wastes, mostly combustible wastes, was adapted as a model. Basic designs of waste heat recovery from incineration system contain the concept and flow diagram of processes, specification of raw wastes, type of incinerator, the operation condition of processes and the heat balance of each process. Based on this basic design, we calculated the lower heating value(L.H.V) of wastes, outlet temperature of boiler, the amount of auxiliary fuel needed for combustion and the recoverable energy from boiler. We additionally proposed the pre-drying waste heat recovery systems and studied the effect of drying of the raw wastes on energy-saving of incineration system. It resulted that as the water contents of the raw wastes were decreased, the L.H.V of raw wastes and outlet temperature of the boiler were increased and moreover, the necessary fuel was reduced beneficially. Consequently, the energy-saving and recoverable emergy from waste heat recovery system could be increased. Thus we expected that the drying equipment with the improved performance could be applied widely to the waste heat recovery system and making solid fuel from sewage sludge and organic waste.