[en] In order to analyze the melting temperature of sintered pellet included impurities of nuclear fuel that is made by dry process(Oxidation and REduction of OXide Fuel : OREOX), it used to be estimated and formulated based on the measured values reported up to now. In general, it is necessary to evaluate the correlation of fuel melting temperature to confirm that the fuel temperature must be kept below the fuel melting temperature during irradiation at any condition. In this study, the experience of melting temperature up to now are summarized and evaluated in order to make the sintered pellet included impurities more reliable by the OREOX process. The effects of plutonium content, oxygen to metal ratio and burnup on MOX (Mixed OXide fuel) fuel melting was examined based on the recent data under the UO₂-PuO₂-PuO_1.61 ideal solution model, and then formularized. For the design, the calculated values by correlation should be have appropriated margin in order to keep under the measured melting temperature. Therefore the following equation is recommended to apply; T=T₀+ΔT_Pu+ΔT_O/M+ΔT_BU+δT δT=-49 Pu Content : 0< Pu≤60% O/M ratio : (1.0-0.01xPu)x2.00+0.01xPux1.61≤OM≤2.00