In order to obtain fundamental data for developing an efficient recovery process of valuable metals from various molten fly ashes, the volatilization behavior of lead was investigated for two types of ash during heating with and without the addition of a chlorinating agent. Changes in the chemical form of lead during heating were followed by applying a sequential leaching. Two types ash, produced from electric resistance and gasification inching furnaces, contained lead in the major forms of PbCli, Pb0 and PbS. Tlw volatilization behavior of lead depended remarkably on the composition of lead forms. MO was the main reactant with chlorine compounds in the ash and was converted to PbC12. Volatilization of lead began around 873K and proceeded with the increase in temperature. When polyvinyl chloride was used as the chlorinating agent, the volatilization of lead was accelerated due to the increased formation rate of PbC1.2. Though PbS was thermally stable and remained in the solid phase during heating, it could be chlorinated effectively by the addition of polyvinyl chloride.