Abstract: Modes of iodine occurrence in 4 Chinese anthracites and the combustion residues obtained at each temperature were extracted with sequential chemical extraction. The coal combustion was simulated with a tube furnace, the effects and mechanisms of heating temperature, heating time, O₂ flow rate and water vapor on iodine release and transformation behavior during anthracite combustion were investigated. The results showed iodine in anthracites can present typically in three main modes of occurrence:organic matter-bound, Fe-Mn oxide-bound and water-soluble form. Temperature had a pronounced effect on iodine release and transformation. Iodine release increased with the increase of temperature, and 500-900℃ was a main stage for iodine release. Before 700℃, some forms of iodine which include water-soluble, ion-exchangeable and organic matter-bound iodine can be almost emitted completely and partly transformed into the carbonate-bound, Fe-Mn oxide-bound and residue-bound iodine. The Fe-Mn oxide-bound iodine may be mainly emitted in 700-900℃, and the residue-bound iodine was emitted partly before 1 100℃.Moreover, the iodine release from anthracite increased with the increase of heating time and O₂ flow rate, and water vapor can obviously promote the iodine release. 93.8%-95.9% of iodine may be emitted in the form of HI and I₂ at the given experimental condition of 1 100℃, water vapor access, O₂ flow rate of 120 mL/min and combustion time of 20 min.