Abstract: In situ electrochemical studies on the oxidation behavior of pyrite in 0.1 M H₂SO₄ solution in the temperature range of 160 to240？C were performed by measurements of electrochemical impedance spectroscopy (E_IS), linear polarization, potentio dynamic polarization and potentio static polarization. Results showed that with the increase of temperature, the anodic current density increased, while the corrosion potential (E_corr), polarization resistance, charge transfer resistance (R_ct) and pore resistance (R pore) decreased. The change of these electrochemical parameters indicated that the increase of temperature promoted the dissolution of pyrite by accelerating the electrochemical step and weakening of the porous passive ？lm. EIS studies with different applied potentials at 240？Crevealed that both R_ct and R_pore decreased with increasing applied potential. As the potential increased to 400 mV, the time constant relating to the porous passive ？lm disappeared. These changes demonstrated that sulfur yield was dependent on the potential, and the sulfur yield approached zero at 400 mV at the temperature of 240？C. The values of E_a indicated that pyrite oxidation kinetics were limited by the rate of electrochemical reaction.