Laboratory studies were conducted to develop an elemental mercury (Hg 0) removal process based on the reaction of H2S and Hg0 using iron oxide sorbents for coal derived fuel gas. It is well known that hydrogen chloride (HCl) is present in the fuel gases of some types of coal, but the effect of HCl on the Hg0 removal performance of iron based sorbents in coal derived fuel gases is not yet understood. In this study, the effects of HCl on the removal of Hg0 from coal derived fuel gases over iron based sorbents such as iron oxides, iron oxide-Ca(OH)2, and iron sulfides were investigated. The iron oxides were prepared by precipitation and conventional impregnation methods. The iron oxide-Ca(OH) 2 sample was prepared by mixing iron oxide with Ca(OH)2 mechanically. Iron disulfide (FeS2) used in this study was a reagent grade chemical. The Hg0 removal experiments were carried out in a laboratory-scale fixed-bed reactor in a temperature range of 60-100°C using simulated fuel gases having the composition of Hg0 (4.8 ppb), H 2S (400 ppm), HCl (0-10ppm), CO (30%), H2 (20%), H 2O (8%), and N2 (balance gas). In the case of iron oxides, the presence of HCl suppressed the Hg0 removal rate. However, the Hg0 removal rate of iron oxide-Ca(OH)2 was not affected by the presence of HCl, because Ca(OH)2 reacted with HCl. The Hg 0 removal performance of FeS2 was not suppressed by the presence of HCl in the coal derived fuel gas.