We verified through experiments that dioxins and related compounds formation through an incineration process of the refuse which contains chlorides and aroma can be disturbed by sulfur component addition. According to the experimental results, the dioxin reduction efficiency is two order higher when solid sulfur, which is contained in refuse, is supplied than when gaseous sulfur is supplied. These experiments were carried out by using 205 mm diameter, 4 000 mm length fluidized bed furnace. Sample refuses are basically made of wood saw dust, poly vinyl chloride or sulfur including coal is added respectively. The effect of dioxins and related compounds reduction by sulfur addition were evaluated under the condition changing molar ratio of S/Cl, keeping furnace gas temperature and residence time constant.