Reduction reaction of synthetic Wustite by graphite through the gaseous intermediates CO and CO₂occuring during the reaction was carried out isothermally within the temperature range 950℃ to 1075℃ in an inert Ar atmosphere with T.G.-D.T.A. analysis technique. The mechanism and the rate of reduction reaction were investigated with modified physico-chemical model derived by Rao and the suitability of Rao`s model to this reaction system was studied, too. The effects of variables such as C/FeO molar ratio, Wustite powder size to the rate of reduction reaction and the compactness of mixed powder were discussed. The overall reduction reaction but the initial stage and the tail part of reaction was considered to be well fitted to the modified physico-chemical model. The activation energy for the Wustite reduction by graphite through the gaseous intermediates is calculated to be 57Kcal/㏖ and this value is reasonably in good agreement with the literature. The rate equation of reduction reaction through the gaseous intermediates was found to be X=2av [1-exp (-kt).〕.