Abstract: The phase transformations and thermal decomposition of the following graphite intercalation compounds (GICs), HNO3-CH3COOH-GIC, H2SO4-GIC and H2SO4-CH3COOH-GIC, were measured by an FTIR-associated TG apparatus. Using Kissinger and Ozawa principles, the kinetic parameters of some typical exfoliation reactions were evaluated and the thermal decomposition mechanism of the exfoliation process was determined. When the heating rate was in the range of 20–80℃/min, the activation energies of the exfoliation reactions were all less than 120 kJ/mol.