Deintercalation of iodine from the compound I-Bi2Sr2CaCu2O8+x was investigated by thermogravimetry (TG) and X-ray diffraction carried out at the different stages of the process. A conventional non-isothermal kinetic analysis and a constant rate thermal analysis of the iodine deintercalation process were performed : as a result, a two step model of the iodine release is proposed.