The thermal decomposition processes taking place in the solid state FeC2O4·2H2O have been studied in Ar using thermogravimetry/differential thermogravimetry/differential thermal analysis（TG/DTG/DTA） and XRD techniques.TG/DTG/DTA curves show that the decomposition proceeds through two well-defined steps in Ar.Mass loss of the thermal decomposition of FeC2O4·2H2O is in good agreement with the theoretica1 mass 1oss.X-ray diffraction（XRD） showed that the final product of the thermal decomposition was Fe3O4.The activation energies were calculated through the Friedman and Flynn-Wall-Ozawa（FWO） methods

and the possible conversion functions had been estimated through the multiple linear regression method and the multiple non-linear regression method respective1y.