The thermal behavior of a purified galena in a chlorine surrounding was determined. The kinetic of the chlorination of galena and the stoichiometry of this reaction between 723 to 973 K (450 to 700C) were measured by thermogravimetry. The microstructural characterization of the solid residues were determined by SEM, EDXS and XRD. The ΔHvap of the produced lead chloride volatilization was obtained by the application of Clausius-Clapeyron equation considering the process in an equilibrium state.